The majority of women who quit smoking during pregnancy will resume smoking during the postpartum period. Little is known, however, about the predictors of postpartum relapses to smoking. Changes in mood and increases in concerns about weight are common during the postpartum period, and these factors may affect women's postpartum smoking behavior. In this paper, we present a model of the relationship among mood, weight concerns and postpartum smoking. Data from previous postpartum relapse prevention trials are reviewed and evidence of a connection between changes in mood and weight concerns to postpartum relapse is presented. Directions for future research on the prevention of smoking relapses during the postpartum period, and the roles of mood and weight concerns in smoking relapse are presented.