Background: Diabetes and morphine play are critical in causing cardiac apoptosis. Objective: This study investigates the effect of eight weeks of aerobic training on apoptosis indices in the heart tissue of diabetic rats with morphine withdrawal syndrome. Methods: In this study, 32 male Wistar rats were randomly assigned into four groups, including diabetic control, diabetic control+morphine withdrawal syndrome, diabetic+aerobic exercise, and diabetic+morphine withdrawal syndrome+aerobic exercise. Subsequently, the induction of diabetes and morphine was done. The training groups participated in an increasing treadmill running program for 8 weeks (3 sessions per week). Then, 24 h after the last training session, the heart tissue was sampled. The levels of Bax and Bcl-2 proteins in the tissue of the left ventricle of the rat heart were measured by the ELISA method. At the significance level of P<0.05, the data was analyzed using the one-way analysis of variance and the Tukey post hoc test. Findings: The amount of Bax was significantly higher in the groups of diabetic control+morphine withdrawal syndrome (P=0.002) and diabetic+morphine withdrawal syndrome+aerobic exercise (P=0.008) compared to the diabetic control group. Also, the level of Bcl-2 protein in the diabetic control group was significantly lower than in the diabetic+aerobic exercise (P=0.004) and diabetes+morphine withdrawal syndrome+aerobic exercise (P=0.04) groups. In addition, the Bax/Bcl-2 ratio was lower in the diabetic+aerobic exercise (P=0.001) and diabetes+morphine withdrawal syndrome+aerobic exercise (P=0.045) groups compared to the diabetic control group. Conclusion: The results suggest that aerobic exercise can be an effective non-pharmacological way to reduce the effects of apoptosis on heart tissue cells in diabetic and diabetic rats with morphine withdrawal syndrome
