Childhood obesity continues to increase, disproportionately affecting Mexican American children. The aims of this review are to (a) assess the literature regarding Mexican American mothers' knowledge and perceptions of childhood obesity, prevention, and their role in prevention; (b) critically evaluate the methodological quality of the research conducted on mothers' perceptions of childhood obesity; and (c) make recommendations for future research on parental perceptions of childhood obesity. Four databases were searched for relevant articles and 22 studies met inclusion criteria and were included in the review. Social cognitive theory was used to sort findings across studies. Major findings included the following: (a) barriers to childhood obesity prevention included lack of education regarding prevention and role modeling, (b) only 23% of studies explicitly used a theoretical framework to guide their study, and (c) most studies used heterogeneous groups to examine perceptions. Implications for future research and practice are presented. (Contains 1 figure and 2 tables.)