Background: Polycystic ovary syndrome (PCOS) is the leading cause of endocrine problem in women of reproductive age, and the commonest cause of anovulatory infertility. Oxidative stress has been implicated in its aetiopathogenesis. Aim: To compare the mean serum level of malondialdehyde and total antioxidant capacity in PCOS patients with infertility in Nnewi, with controls (tubal factor infertility). Methods: The study involved 64 cases and 48 controls in age 18-45years. Serum MDA and TAC levels were estimated. The data was analyzed using statistical package for social science (SPSS software package version 21.0).