Continuity mistake: When Betty is shown the crime scene photo of Melanie's body, Melanie is inches away from a pallet and the jacket covers most of her torso leaving only the right arm exposed. In the flashback scene, Melanie is feet away from the pallet and the jacket mainly covers her chest and face, leaving both arms uncovered.
Continuity mistake: On the note Mary Alice receives that leads to her suicide, the position of the three sentences changes throughout the series. In episode 1.1 (Pilot), all three lines are written on the top half of the note (above the crease), but in later episodes the first two lines are on the top and the third is on the lower half. The left margin also gets smaller, and the handwriting varies slightly.
Continuity mistake: In "Getting Married Today," Gabby's hair in the beginning has her bun high on her head and her tiara is visible from the front. When Bree walks in, and when she overhears Victor and his father talking, her tiara is farther back on her head and no longer visible from the front.
Continuity mistake: Season 2, Episode 23: "Remember, Part 1" - In the 1994 flashback where Bree introduces herself to Mary Alice and forces her son Andrew to apologise when he stole a ornamental garden frog, the position of the frog changes between shots as Bree hands it to Mary Alice.
Continuity mistake: Throughout the series, any time you see into the front door of the Scavo house (from an exterior shot), there is a blue wall with a table in front of it, however, interior shots show that the front door leads to the lounge, with the staircase opposite the door.
Continuity mistake: Season 7, Episode 23 - "Come On Over For Dinner": Right after Carlos kills Alejandro with the candlestick, he throws the candlestick to the left of Alejandro's body. But a few seconds later the candlestick has suddenly moved to near Alejandro's head.