In an effort to contribute to society and to make her boys useful at the same time, Lois "volunteers" Malcolm, Reese and Dewey for charity work at a local church. The boys are assigned to sort giant piles of donated clothing, game, appliances etc. Initially irritated at their new task, they realize the donated stuff is a lot nicer than their own possessions, and they begin swapping out their old stuff with the second-hand items. The boys soon make a enterprise out of their charity assistance, going as far as to sell things to the neighborhood kids - that is until Hal finds out. Meanwhile, Francis must come to grips with the fact his fabulous job in Alaska is not quite what he expected.
Malcolm is a regular high school kid trying to navigate his way through life despite the various obstacles thrown in his way a complete misunderstanding of girls, the constant burden of masterminding plans to get himself and his brothers into or out of trouble, and a miserable job at the Lucky Aide not to mention a severe case of teen angst.
Although Malcolm has a genius IQ, he can't seem to make sense of the opposite sex, much less his embarrassing family. Lois is the outspoken, opinionated mom, who still manages to rule the roost even though her boys are growing wise to her crafty ways. Hal, a dad who is just a bumbling, big kid at heart, often finds himself creating more chaos than his five boys combined.