We aimed to investigate the effects of melatonin and resveratrol on diabetes-related papillary muscle dysfunction and structural heart disorders. The protective effect of resveratrol and melatonin supplementation on cardiac functions was investigated in a diabetic elderly female rat model. 16-month-old rats (n=48) were allocated into 8 groups. Group1: Control, Group2: Resveratrol Control, Group3: Melatonin Control, Group4: Resveratrol and Melatonin Control, Group5: Diabetes, Group6: Diabetes Resveratrol, Group7: Diabetes Melatonin, Group8: Diabetes Resveratrol and Melatonin. Streptozotocin was injected intraperitoneally to the rats for experimental diabetes induction. Thereafter, resveratrol (intraperitoneal) and melatonin (subcutaneous) were administered for 4 weeks. Resveratrol and melatonin had a protective effect on the contractile parameters and structural properties of the papillary muscle, which was impaired by diabetes. it has been presented that diabetes impairs the contractile function of the papillary muscle for each stimulus frequency tested and the responses obtained as a result of Ca+2 uptake and release mechanisms from the Sarcoplasmic reticulum, and it has been observed that these effects are improved with resveratrol and melatonin injection. The decrease in myocardial papillary muscle strength in the diabetic elderly female rat can be reversed with the combination of resveratrol, melatonin and resveratrol+melatonin. Melatonin+resveratrol supplementation is no different from melatonin and/or resveratrol supplementation. Resveratrol and melatonin supplementation may have a protective effect on cardiac functions in a diabetic elderly female rat model