Introduction: The use of many drugs is associated with kidney complications. Sitagliptin is an antidiabetic drug. Due to polycystic ovary syndrome (PCOS) having a direct relationship with insulin resistance, the use of this drug in the treatment of PCOS is recommended, and in this research, its effect on the renal function of rats with PCOS was investigated. Methods and Materials: 40 female rats (220-200g) were selected and divided into 5 equal groups. All rats, except the control group (healthy mice), were induced with polycystic ovary syndrome with 1 mg/kg/bw of letrozole solution orally and daily (40 days). After confirming the induction of PCOS, one group without treatment (PCO) one group with metformin 500 mg/kg/bw, and two groups with doses of 30 and 60 mg/kg/bw of water-soluble sitagliptin were treated for 40 days. Then, following the animal's ethics, rats were anesthetized and blood was taken from them. Sex hormones, glucose, and the parameters for evaluation of renal function were measured in serum. Data were analyzed by one-way analysis of variance and Tukey's test. Blood Urea Nitrogen Results: Taking of sitagliptin and metformin in the treatment groups, in addition to improving blood glucose, progesterone, and testosterone hormones, increased the serum levels of blood urea nitrogen, creatinine, uric acid, direct and total bilirubin in PCOS rats at a significant level (p<0.05) reduced. Also, the reduction of total protein and albumin in PCOS rats was significantly increased with the use of two drugs. Metformin showed more effect than sitagliptin, especially with a lower dose. Conclusion: According to these results, sitagliptin can improve renal function in a similar effect to metformin with a positive effect on regulating sex hormones and blood glucose in PCOS rats. Therefore, more research on the mechanism of this drug is recommended, maybe it will be considered as a new drug in the treatment of PCOS.