In this article, deviant action is analyzed on the basis of ideas derived from Gottfredson and Hirschi's self-control theory. Presumedly, self-control in interaction with opportunities can explain deviant action. This assumption is elaborated using the concept of high- and low-cost situations from rational choice theory. From this point of view, the hypotheses are that self-control predicts deviant action in low-cost situations, whereas utility predicts deviant action in high-cost situations. Two test strategies are employed in an empirical examination of these hypotheses. A standardized questionnaire was presented to a sample of 494 German adults aged 18 to 80. The results of both test strategies show that the assumptions of an interaction effect between self-control and opportunities are fundamentally supported. (Contains 6 notes, 6 tables, and 9 figures.)