Background and Objectives: Resistin is a new hormone that is secreted from adipocytes which can be associated with obesity and insulin resistance. The effects of exercise trainings on resistin levels and its association with metabolic indices are unknown. The aim of the present study was to determine the response of serum resistin to aerobic exercise and its association with metabolic indices in women with type 2 diabetes Mellitus. Materials and Methods: In this quasi-experimental study, 40 women with type 2 diabetes were randomly divided into two experimental (n=20) and control (n=20) groups. The experimental group received 12 weeks of aerobic exercise, 3 times a week for 20-50 minutes at 50-70% of maximum heart rate. The control group was sedentary during the same period. Blood samples were collected to examine the biochemical variables in pre-and post-tests. Results: The mean of age and BMI was 59/70±5/28 years and 31/80±3/87 respectively. Aerobic exercise decreased weight, body fat percent, body mass index, lipid profile, fasting glucose and glycosylated hemoglobin while resistin was increased (P≤0/05). Insulin levels and insulin resistance did not change significantly (P≥0/05), also there was a significant inverse correlation between resist in and cholesterol in post-test (P≤0/05). Conclusion: According to the increase in resistin levels and because of no significant change in insulin resistance, it is unlikely that resistin linked obesity to insulin resistance in type 2 diabetes Mellitus.