Continuity: In the episode "Christmas at Plum Creek", Laura's horse Bunny is referred to as being male. However, in the episodes "Bunny", "The Race" and "Journey in the Spring", the same horse is always referred to as being female.
Errors in geography: In the episode "The Lord is My Shepherd", Laura runs away from home and stays on top of a mountain, even though there are no mountains whatsoever in Walnut Grove, Minnesota.
Continuity: In the episode "The Circus Man", when Mr. O'Hara is telling Laura that his secret potion doesn't work, her braids keep moving from in front of her to in back of her.
Continuity: In the second part of the two part show "Home Again", Albert and Charles are in Mr. Edwards cabin as Albert is going through withdrawal. In one scene, he gets the shakes and then throws up all over himself. In the next scene, the shakes start again and his pants are completely clean.
Continuity: Slick city guy Royal Wilder and his wife Millie stick Laura and Almanzo with the care of their two obnoxious sons so that they can go on a vacation. A couple of seasons later, a new Royal shows up (who Almanzo claims not to have seen in ten years). Now he's a sickly farmer with a pre-teen daughter, Jenny, and no sons or wife anywhere in sight.
Anachronisms: In some episodes, when Caroline moves the right way, one can see that she is wearing a bra. The series is set in the 1870s to the 1880s, and bras were not invented until 1912.
Crew or equipment visible: One of the inconsistencies of the show was its time-line. In the shows first few seasons it would jump back and forth between the the mid 1870s to the early 1880s with little regard for continuity.