Continuity mistake: In the first episode, when they meet as children, they seem to be about the same age. But later episodes refer to Greg as a 32-year-old lawyer, and after 2-3 years of marriage, Dharma is having her rebirthday party, which happens every 7 years. She is 28 then, so it seems like Greg is at least 5 years older, which is very noticeable as children.
Dharma & Greg (1997)
1 continuity mistake in season 2 - chronological order
Starring: Jenna Elfman, Thomas Gibson, Joel Murray, Mimi Kennedy
The Official Dharma & Greg Episode of the 1998 Winter Olympics - S1-E17
Continuity mistake: While the guys are talking about the winter Olympics, the position and level of the bottle keeps changing all through the scene.
Kitty: Oh, Gregory, darling, every bride thinks she wants to cook a Thanksgiving dinner and it always ends up the same. Someone cries, someone is rushed to the emergency room and a perfectly lovely bird gets wasted. Which, if I don't eat soon, will be me.