Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disorder. Pomegranate juice (PJ) has been known to play anti‐inflammatory and antioxidant roles. However, the effects of PJ on inflammation, oxidative stress, and sex hormones in PCOS patients are very little studied, and thus more studies are needed. This randomized controlled trial enrolled 44 women diagnosed with PCOS according to the Rotterdam criteria, body mass index (BMI) ≥ 25 kg/m 2, and aged 18–40 years old. Participants were randomly assigned to take 45 ml/day of concentrated PJ or a control group without intervention. Some biomarkers of sex hormones, inflammation, and oxidative stress were quantified at baseline and after the 8‐week intervention. Compared with the controls, serum testosterone levels were significantly decreased in overweight and obese women with PCOS who supplemented with concentrated PJ (−0.004 ± 0.013 vs. 0.039 ± 0.013, p = .039). However, we did not observe significant differences in luteinizing hormone (LH) and sex hormone‐binding globulin (SHBG) levels and inflammation and oxidative stress factors between the two groups after adjustment for confounding variables. An 8‐week supplementation with concentrated PJ could effectively improve testosterone levels in overweight and obese women with PCOS. This study was registered at www.irct.ir (IRCT20191109045383N1).