This study aimed to determine the relationship between the metabolic and endocrinological pathologies in polycystic ovary syndrome (PCOS) and the levels of arsenic, chromium, cadmium, lead, mercury, antimony, zinc, and copper to evaluate the relationship of these toxic metals with inflammatory/oxidative parameters. This study included a total of 154 patients (84 with PCOS, 70 healthy volunteers). Metabolic and endocrine parameters and arsenic, chromium, cadmium, lead, mercury, antimony, zinc, and copper serum levels of the patients were compared between the groups. Considering the action mechanism of toxic metals, serum malondialdehyde (MDA), superoxide dismutase (SOD), serum total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), tumor necrosis factor-alpha (TNFα), and high-sensitivity C-reactive protein (HsCRP) levels were determined. Serum TAS (p = 0.002), OSI (p = 0.006), SOD (p = 0.006), zinc (p = 0.010), and copper (p = 0.030) values were statistically lower whereas TOS (p = 0.008), MDA (p < 0.001), HsCRP (p < 0.001), TNFα (p < 0.001), antimony (p < 0.001), cadmium (p < 0.001), lead (p < 0.001), and mercury (p < 0.001) levels were significantly higher in the PCOS group than those determined in the control group. Antimony was positively correlated with fasting glucose (FG) and HOMA-IR while cadmium, in addition to FG and HOMA-IR, positively correlated with insulin and lead had a positive correlation only with FG (p < 0.05). Also, these three heavy metals correlated positively with some oxidative system and inflammatory parameters and negatively with the antioxidant system parameters (p < 0.05). In conclusion, heavy metal exposures in PCOS may be related to insulin resistance and hirsutism through oxidative and inflammatory mechanisms. This approach can be used to identify the risky patient group and to develop new treatment modalities.