This article proposes a theory of personal action designed to foster a social-contextual analysis of personal change. Self-regulation theory, social action theory, problem-solving skills, & the importance of social support are presented as premises for this model. The author asserts that public health interventions can enhance action capabilities by altering inaccurate schemas & providing useful knowledge & skills. Implications of this model on such behaviors as smoking, drinking & adhering to exercise regimens are included. (185 refs) (SC)