FBI agent Malcolm Turner latest assignment sends him to small-town , where he's assigned to trap a brutal bank robber (and a recent prison escapee) who they suspect will be coming down to visit his ex-girlfriend Sherry and her son. Malcolm sets up a stakeout across from the home of a larger-than-life matriarch known as Big Momma, who's about to be visited by Sherry. but there's one big problem: Big Momma has unexpectedly left town. So Malcolm, decides to impersonate the cantankerous Southern granny. . In the mean time, Malcolm starts falling for Sherry, who may or may not be hiding some stolen cash.