Self-control cognitions arise right before or after someone gives in to an unwanted habit. This paper reports on the development of the 11-item Self-Control Cognition Questionnaire (SCCQ) in a series of three studies. In the first study (N = 308), we found that the SCCQ has a two-factor structure and is reliable. The factors were named “Giving way is rewarding” and “Resistance is impossible.” The construct validity of the SCCQ was assessed in the second study (N = 138). As expected, the SCCQ correlated positively and strongly with the preoccupation with unwanted habits and with the experience of craving, and correlations with one’s tendency to consider the long-term consequences of actions were small. The third study demonstrated that the SCCQ discriminates between patients with habit disorders (N = 63) and controls with non-pathological unwanted habits (N = 106). The SCCQ was sensitive to therapeutic change in two patient samples, one suffering from hair pulling disorder and the other from pathological skin picking. The SCCQ is applicable to unwanted habits in general, both pathological and non-pathological. It is proven to have sound psychometric properties and is suitable for use in practice.