The series has had numerous writers and contributors, including guest writers who have developed whole episodes. Given this, along with the fact that the animation is outsourced overseas, it is understandable why such continuity errors exist in the series. Most continuity errors occur when later episodes contradict what had been established in the first and second seasons. Regardless, many of these errors are blatant and inexcusable to hardcore fans who value the show's usual consistency.

Peggy Hill is shown to have two different mothers. Prior to the ninth season, whenever Peggy's mother is seen (in the present or in flashbacks), she is portrayed as an older version of Peggy, a stereotypical 1950s housewife with a hatred for the use of contractions; however, in the ninth season's premiere episode, Peggy's mother is a lean, leather-skinned rancher who shows disdain for Peggy and lives on a secluded ranch.

Peggy's growing up in Montana has been consistent. However Peggy was shown to live in Arlen with her mother when she met Hank during high school (they attended different schools). In the episode "A Rover Runs Through It", Peggy's mother reveals that a post-school Peggy left the family ranch in Montana for Arlen, Texas. This "second" mother never lived in Arlen.

In the second season episode "How to Fire a Rifle Without Really Trying", Hank is unable to handle a gun, but in the next episode, "Texas City Twister", a shot of Hank's den shows a trophy Hank won for skeet shooting, though shooting skeet with a shotgun and handling a rifle could be considered separate skills. However, Hank's lack of skill is supposed to be the result of a psychological block provoked by his father's criticisms, which Hank now fears to transmit to Bobby.

In the sixth-season episode "My Own Private Rodeo", Dale's father appears, looking completely different from the character that appeared in a flashback in the first season episode "The Order of the Straight Arrow." although seeling as the man has aged many years, it could still be the same figure the father was portrayed as, but it is unlikely. It should also be noted that Dale's father was previously shown as having the same voice as Dale in the episode "Now Who's the Dummy?", but in the episode "My Own Private Rodeo", Dale's father has the voice of a flamboyant homosexual stereotype. (it is possible that in the years since dales birthday, his father's voice changed, but again, it is unlikely.)

In earlier seasons, Hank's truck is notably identified as a 1993 Ford Ranger. However, in the episode "Chasing Bobby", It becomes a 1983 Ford Ranger, now on its last leg. Regardless, it was shown that Hank bought his truck brand-new slightly prior to Bobby's conception. If one was to subtract Bobby's age from original air dates, neither model year makes sense.

Hank often reminisces about his experience on his high school football team. Hank, Boomhauer and Bill all played on the team in the early 70s under Coach Sauers who took the team to state. (Dale was the team's towel boy.) Ambiguity also surrounds Hank's position on the championship team. In the episode "Now Who's the Dummy?", Hank's jersey reads 10, a number commonly reserved for quarterbacks. In the episode "Bills are made to be Broken" Hank is seen playing on the offensive line, however it is implied that Hank moved from running back to center in goal-line situations. (Hank is also quoted in other episodes as saying "blocking for Bill"). In the episode "Love Hurts and So Does Art", Hank refers to himself as a running back. And finally, in the episode "What makes Bobby Run?" Hank is seen catching a touchdown reception from the wide receiver position. Usually Boomhauer is the quarterback and Bill is the fullback. In episode 9 of season 3 "Pretty Pretty Dresses", Boomhauer is at quarterback; Bill is at fullback; Hank is at halfback and Dale is towel boy. Hank refers to himself as holding the "single season rushing record" and in the episode "Bills Are Made To Be Broken", Bill is said to hold the record for most career rushing touchdowns as a defensive tackle. This is not uncommon as many high school players play both offense and defense. Boomhauer is again seen at quarterback. Hank can be seen wearing a uniform number commonly associated with running backs, while Bill is wearing one normal of a lineman. This could be explained in that Bill wears the same jersey number (72) as former Chicago Bears defensive lineman William Perry. Perry was famous for lining up as a fullback when the Bears offense was near the goal-line, hence Bill's football playing days could be seen as a tribute to Perry. Though it should be noted that position numbers are not as stringent in high-school and college football as it is at the professional level.

In the episode, "Hank's Cowboy Movie", Hank is seen grilling on a barbecue grill and remarks, "I made that barbecue out of two barbecues." This is in direct conflict with Hank's character and loathing for charcoal-based grilling.

In the episode "A Beer Can Named Desire", the Cajun heritage that explains Bill's middle and last name is revealed. His relatives in Louisiana are rich plantation owners, which some view as a discrepancy because his father had been described as a semi-abusive lower-to-middle class man. Bill's relatives' status does not constitute a true discrepancy because it is possible his parents/father were of a different economic class. Also, Bill does mention in the episode moving from the area at a young age. Also regarding Bill's family, two episodes have featured Bill's cousin Gilbert (pronounced "Zhill Bear"). Both times Bill's friends act as if it is the first time they have met him. in the episode one, Gilbert comes to Bill's family reunion, and Bill is told that the family money has run dry, and that he and Gilbert are the last of the Dauterive bloodline.

The trailer park in which Luanne grew up is called "Shiny Pines." But in the episode "Board Games," it is referred to as "Shady Pines."

In the season 1 episode "Plastic White Female," Hank is seated at the dining table reading the newspaper - its masthead reads the Arlen Courier. However, in all other references to Arlen's daily newspaper (season 3 - "Peggy's Headache," season 9 - "Smoking and the Bandit" and season 10 - "Bystand Me"), the publication's name is the Arlen Bystander.

In Episode 1 The Child Protection Agency office reads Arlen County, but in all later episodes it is called Heimlich County with the exception of Nancy Gribble's occasional reference to Arlen County in later episode(s).

Enrique's voice changed to have a more authentic Mexican-American accent in later seasons. He speaks less frequently in early seasons and has a generic non-accented voice.

In the episode "The Order of the Straight Arrow" (Season 1, Episode 3), a young Hank says he wants to work in propane when he grows up (if his grades are good enough). This contradicts a later episode in which a young Hank is selling blue jeans to a younger Buck Strickland who offers him a job selling propane, as well as another episode where he tells Bobby he "didn't discover propane until he was in his twenties".

The events in the episode "SerPUNt" (season 11, episode 2) are at odds with the episode "Not in My Back Hoe" (season 4, episode 8) in which Hank indicates that he has a septic tank instead of a sewer connection. When Bill gets a new tank and they can't find where the old one is, Bill asks Hank where Hank's septic tank is. Hank answers: "Side lawn, eight feet out; nine feet, seven inches from the pavement."

Hank's barber, Jack, has always maintained the same voice, Brian Doyle-Murray, however he has been drawn in two forms. In earlier episodes he was shown as a middle-aged man with a thin mustache. Later episodes show him as a much older man without a mustache.

In the episode "Hank's Bad Hair Day" (Season 4, Episode 19), Hank's barber Jack goes crazy and Bill becomes Hank's barber. Although the episode doesn't officially retire Jack, it is assumed that he has at least retired. Since that episode, Jack has appeared in at least two episodes; "My Hair Lady" (Season 8, Episode 11), and "Luanne Gets Lucky" (Season 11, Episode 4).

All the main white characters worship at Arlen First Methodist Church, as does John Redcorn. The Souphanousinphones are Buddhists and follow the Dalai Lama (Ted Wasonasong converted from Buddhism to the Episcopal Church because it was "just good business"), although in scenes at Arlen First Methodist Church, the Souphanousinphones have been featured worshiping as background characters. Revenge Of The Lutefisk

In the episode "Shins of the Father" (Season 1, Episode 8) Bill wears Red shorts to Bobby's birthday party. During one wide angle shot Bill is shown to be wearing blue shorts. The very next shot Bill's shorts are Red again