BACKGROUND Preptin and amylin are pancreatic hormones which participate in glucose homeostasis. This study aimed to evaluate how serum preptin and amylin levels are altered in polycystic ovary syndrome (PCOS) patients and healthy women based on BMI groups (<25 kg/m² and ≥25 kg/m²). MATERIAL AND METHODS This was a prospective randomized control study of 40 PCOS patients and 40 healthy women who were matched with respect to BMI (<25 kg/m² and ≥25 kg/m²). RESULTS When compared to the healthy women, PCOS patients had significantly higher ovarian volumes, Ferriman-Gallwey scores, and free and total testosterone levels, but significantly lower amylin concentrations (p=0.001, p=0.001, p=0.049, p=0.021, and p<0.001, respectively). Both the normal-weight and overweight PCOS patients had significantly lower amylin levels than the normal-weight and overweight controls (p<0.001, p=0.009, p=0.001, and p=0.001, respectively). Amylin levels were negatively and significantly correlated with the Ferriman-Gallwey scores (r=-0.272, p=0.001) and ovarian volume (r=-0.206, p=0.007). Serum preptin levels were not elevated in either group. CONCLUSIONS Serum preptin levels are statistically similar in PCOS patients and BMI-matched healthy controls. Serum amylin levels are significantly higher in healthy controls than PCOS patients whether they are slim or overweight. These findings suggest the presence of mechanisms that can prevent the elevation in serum amylin concentrations that can occur in response to the impaired glucose metabolism in PCOS patients.