Objective: Collagen type I is abundant in the outer layers of capsular stroma and theca externa in the ovary. C-terminal propeptide of Type I collagen (CICP) is the measurable form of type I procollagen in serum. Circulating CICP levels are indicative of collagen production. This study was designed to determine the serum levels of CICP and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels in women with Polycystic Ovary Syndrome (PCOS). Material and Methods: This study included twenty-five women with PCOS in the study group and twenty healthy women in the control group. Serum lipid sub-fractions, fasting glucose and insulin, hormone (gonadotropins, androgens), CICP and TIMP-1 levels were measured. Homeostasis model assessment (HOMA-IR) was used to estimate insulin resistance. Results: Serum luteinizing hormone (LH) and fasting insulin levels, LH/follicule stimulating hormone (FSH) ratio, free androgen index (FAI) and HOMA-IR values were higher in patients with PCOS compared with healthy women. A significant increase in CICP level was observed in subjects with PCOS, and TIMP-1 level was found to be significantly decreased. HOMA-IR value was positively correlated with CICP level, but inversely with TIMP-1 level. The best cut-off values for CICP and TIMP-1 were >49.94 ng/mL (sensitivity 92.6% and specificity 65%) and <275.99ng/ml (sensitivity 92.6% and specificity 40%) respectively. Conclusion: Elevated circulating CICP levels may be associated with thickened tunics albuginea in women with PCOS. However, the exact role of CICP in the pathogenesis of the disease remains to be elucidated.