Background and Aim: Brown adipose tissue (BAT) is a specialized type of adipose tissue that dissipates energy as heat and plays a crucial role in body weight regulation. UCP-1 and PGC-1α are key players in the conversion of white adipose tissue (WAT) to BAT. This study aimed to investigate the effects of aerobic exercise performed at different times of the day on the expression of these genes in the adipose tissue of diabetic mice. Materials and Methods: In this experimental study, 30 adult male NMRI mice aged 8-10 weeks with an average weight of 26 ± 2.3 grams were randomly divided into six groups (five mice per group): two healthy control groups (light and dark phases), two diabetic control groups (light and dark phases), and two diabetic groups with exercise intervention (light and dark phases). The diabetic groups were fed a high-fat diet and injected with streptozotocin. Aerobic exercise was performed for eight weeks at a moderate intensity (50-60% of maximum running speed). At the end of the study, the expression of UCP-1 and PGC-1α genes in adipose tissue was measured using real-time PCR. Data were analyzed using GraphPad Prism 10 software and ANOVA with a significance level of 0.05 Conclusion: The findings of this study indicate that aerobic exercise performed in the evening significantly increased the expression of PGC-1α in diabetic mice. This increase in gene expression suggests the potential for improving metabolic status in this animal model.