Objective: The aim of the study was to compare the effects of 16-week treatment with two insulin-lowering therapies on the clinical, endocrine-metabolic and ovulatory parameters in women affected by polycystic ovarian syndrome (PCOS). Material and methods: A total of 70 patients attending the Gynecology OPD of Holy Family Hospital, Okhla, New Delhi, with clinical features of PCOS in the age group of 17-35 years, between June 2015 and May 2016, were selected. Patients were randomly distributed into two groups with 35 patients each. Group 1 received myoinositol (MYO) 2 g/day, while Group 2 received metformin 500 mg/day twice-daily. Baseline anthropometry, biochemical investigations and pelvic ultrasonography were done and repeated after 16 weeks. Results: Modified Ferriman-Gallwey (mFG) score was reduced from 4.66 ± 4.06 SD to 3.56 ± 3.29 SD in Group 1 and 4.94 ± 4.05 SD to 3.87 ± 3.24 SD in Group 2; the fall in Group 1 was more significant than Group 2. Fasting insulin decreased from 13.90 ± 6.88 SD to 11.66 ± 6.05 SD in Group 1 and from 12.85 ± 4.46 SD to 11.78 ± 4.39 SD in Group 2; reduction was highly significant in Group 1 than Group 2. Results for luteinizing hormone (LH) were not significant. Free testosterone decreased from mean of 1.47 ± 0.37 SD to 1.37 ± 0.37 SD in Group 1 and from 1.43 ± 0.37 SD to 1.36 ± 0.36 SD in Group 2; the fall in Group 1 was more significant than Group 2. Conclusion: Metformin is effective in reducing the metabolic and hormonal parameters and improves fertility. MYO not only improves all the above parameters but also decreases insulin resistance significantly. Thus, MYO supplementation is essential in the management of PCOS to improve insulin sensitivity.