Positive psychological states are linked to superior cardiac outcomes, possibly mediated through increased participation in health behaviors. Trained study staff conducted in-depth semi-structured interviews in the hospital and 3 months later for 34 patients diagnosed with an acute coronary syndrome. These interviews focused on positive psychological states, cardiac health behaviors, and their connection; the interviews were transcribed and independently coded using directed content analysis. Both optimism and positive affect were associated with completion of physical activity and healthy eating in a bidirectional manner. In contrast, gratitude, while common, was infrequently linked to completion of health behaviors.