The show starred Frankie Muniz as Malcolm, the third-born of four, then five later in the series (and possibly six, in the last episode), sons of Lois and Hal. The oldest, Francis, was shipped off to military school, leaving three brothers: Reese, Malcolm, Dewey and starting in season four Jamie living at home, Malcolm being the middle child still at home. The show's early seasons centered on Malcolm and the rigors of being an adolescent and enduring an eccentric, although eerily normal, life. Later seasons gradually explored the other members of the family and their friends in more depth.
The series was different from many others in that Malcolm broke the fourth wall and talked directly to the viewer; it was shot using a single camera; and it used neither a laugh track nor a live studio audience, just sound effects. Emulating the style of hour-long dramas, this half-hour show was shot on film instead of video. Another unique aspect is that the cold open of every episode is unrelated to the main story.