Revealing mistakes: In several episodes (mostly from season 5 onward), you can see ceiling segments missing from the manor when low angle shots are used. The ceiling panels are in large square, sometimes rectangular segments that are able to be removed to position studio lights for certain shoots. In many scenes these are missing, revealing the open studio space above the set.
Continuity: The order of pages in the Book of Shadows is continuously changing. For example, in season Three Phoebe wrote about Cole Turner on the page next to Balthazor information, she placed a photo inside it else well. However during season four the page is once found blank and also found with information on something else.
Anachronisms: Throughout the series, stock aerial footage of San Francisco is used. The footage often contains the Embarcadero Freeway (I-480/CA-480) a structure that used to run along the San Francisco Bay north of the Bay Bridge. The structure was removed in 1991, a full seven years before the series started.
Revealing mistakes: In many episodes, when the front door of the manor is opened in an exterior shot there is clearly a solid wall behind it, however in the sets there is a long corridor behind the door.
Revealing mistakes: in several cases throughout the series the view seen through the attic window is inconsistent with the houses location (possibly the studio grounds).