Objective: We investigated mothers' possession and display of action competence to counteract or prevent overweight and eventual obesity in their children. Action competence is defined as a personal resource where the most important aspect is the individual's wish to take action and to believe in its benefit. It unfolds within the room for action as experienced by the individual due to action obstacles and action potentials. Methods: In a case-control study, mothers of 111 overweight children (MOC) were compared with mothers of 149 nonoverweight children (MNC). They underwent a semistructured interview about action competence, lifestyle, and their 7- to 9-year-old children. Results: Compared to MNC, MOC considered it more important to change habits, both for themselves (p = 0.003) and their children (p <0.001). MOC were more motivated to change habits (p <0.001), assessed their action competence to be higher (p <0.001), and felt to a greater extent that they supported their children to achieve an appropriate weight (p <0.001) compared with MNC. No difference was found between MOC and MNC in the assessment of their own room for action and their children's room for action. Conclusion: Self-assessed room for action was not limited for either MOC or MNC, and MOC even assessed their action competence to be greater.