PURPOSE: To determine the weekly effect of exercise-based CR on perceived stress and mood states in patients with coronary artery disease (CAD). METHODS: Twenty-one patients with CAD (age = 58.3 ± 10 years, weight = 76.5 ± 13 kg, BMI, 28 ± 4.7 kg/m², VO2max = 12.4 ± 3.7 ml/kg/min), were measured every week for eight weeks on perceived stress and mood states (fatigue, vigor, tension, friendship, anger and depressed state), using the scale of perceived stress (EEP-10) and the profile of mood states (POMS). Functional exercise capacity and estimated VO2max were obtained based on the 6-minute walk test (6MWT) at pre and post CR. A repeated measure ANOVA was used to determine outcomes differences. Effect sizes were also calculated and probability was set at level p<0.05. RESULTS: Patients reduced stress (F (8-160) = 7.72, P < 0.01, η²=.279) from (11.5 ± 4.3 to 5.7 ± 4.3 score) 50% post CR. Stress was reduced at week 1 from (11.5 ± 4.3 to 8.0 ± 4.6, P = 0.049) and was maintained subsequently. Fatigue decreased (F (8-160) = 4.3, P = 0.016, η2 =.178) from (6.3 ± 5.2 to 2.6 ± 2.3, score), 58% after CR. The change in fatigue was observed until week 7 from (6.3 ± 5.2 to 3.1 ± 3.8, P =.010). Vigor increased (F (8-160) =7.1, P = 0.0019, η2 =.263) from (12.2 ± 4.6 to 16.0 ± 3.6, score), 31% more post CR. The improvement in vigor was observed until week 5 from (12.2 ± 4.6 to 3.6 ± 16.1, P = 0.009) and it was maintained afterward. Tension decreased (F (8-160) =7.8, P = 0.005, η2 =.281) from (6.0 ± 4.5 to 2.4 ± 2.8 score), 60% less post CR. The decrease in tension was observed at week 3 from (6.0 ± 4.5 to 3.2 ± 3.1, P = 0.037) and it was remained at week 5, 6 and 8 (P = 0.004, P = 0.005, P = 0.005), respectively. Friendship only improved 12.5% at week 5 from (15.2 ± 3.1 to 17.1 ± 2.7, P = 0.015). In addition, VO2max improved 21.7% from (12.4 ± 3.7 to 15.1 ± 3.9 ml/kg/min, ES = 0.68, P < 0.01) after CR. Similarly, the 6MWT distance improved 26% from (444 ± 86 to 559 ± 88 m, ES = 1.2, P < 0.01). CONCLUSION: Our eight-week exercise-based CR was effective on reducing the levels of perceived stress and improving the mood states of vigor, fatigue and tension. Perceived stress improved at week one, tension decreased at week three and vigor and friendship took five weeks to change. We need more studies to evaluate if these benefits persist long after completing a cardiac rehabilitation program.