This article presents a test of the key propositions from self-control theory. The authors explore the mediating role of parenting practices (i.e., use of discipline and display of approval) for the link between parental stress via interparental conflict on self-control development. The results of the study, which are based on self-reports from a national probability sample of 1,148 mothers and children, show partial support for this mediating view. The results are qualified by methodological and analytical limits. Despite the limits, the study represents an addition to the growing body of literature on self-control theory. (Published Abstract)