A theoretical distinction within self-control, between stop control and start control, was investigated in two studies. Study 1 consisted of a pilot study in which expert ratings of existing self-control items were used to distinguish between stop and start control items and a confirmatory factor analyses of these items using a student sample (N = 474). Also, stop and start control were related to overall affect and behavioural outcomes. Stop control was negatively related to negative affect, whereas start control was positively related to positive affect. Study 2 (N = 226) replicated some of these findings; stop control was the best predictor (−) of smoking and alcohol consumption whereas start control was the best predictor (+) of exercising and studying. Copyright © 2010 John Wiley & Sons, Ltd.