Objective: To explore a selection of psycho-social variables with potential influence on exercise and dietary behaviors in patients with cardiovascular disease and diabetes in Saudi Arabia and to elicit salient directions and themes for further examination on a larger scale. Method: This was a phenomenological qualitative study informed by the Self-Determination Theory and the COM-B Model. It involved fully structured, open-ended interviews administered to 8 inpatients at a governmental hospital in Riyadh between October and December 2020. Data was examined using a hybrid of deductive and inductive content analysis. Results: Patients with a higher degree of basic psychological need satisfaction lived healthier lives and displayed more positive emotional responses. We detected differences between physical activity and nutritional behavior in terms of the associated perception of autonomy and competence, as well as motivational quality. The family emerged as major social support source for both behaviors. Environmental opportunities provided for exercise and diet support were commonly perceived as insufficient. Conclusions: We suspect the level of perceived psychological need support to be linked to the patients’ behavioral and psychological outcomes. We also expect local inequalities in the available behavior change support across different health behaviors and the need to adequately foster patient autonomy in clinical interventions in Saudi Arabia.