Two studies tested the hypotheses that (1) action orientation (vs. state orientation) is positively correlated with age across adulthood and (2) action orientation aids the self-regulation of one's feelings, thoughts, and behavior during the pursuit of a dieting goal. Hypotheses were partly confirmed. In Study 1, N = 126 overweight women (age: 19–77 years) intended to lose weight by means of a low-calorie diet. In Study 2, N = 322 adults (age: 18–82 years) reported on their action orientation to replicate the association of age and action orientation found in Study 1. Study 2 corroborated only the expected positive association of age and decision-related action orientation. In Study 1, decision-related action orientation predicted higher affective well-being during the diet as well as less self-reported deviations from the diet; failure-related action orientation predicted lower levels of rumination in response to dieting failures. Action orientation partially mediated the negative effects of age on deviations and rumination (see Hennecke & Freund, 2010). Weight loss was not predicted by action orientation. We discuss action orientation as one factor of increased motivational competence in older adulthood.