Background: Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age. Due to the logistics of diagnosis and lack of consensus on the diagnostic criteria, there are very few prevalence studies in the community. This study was aimed to assess the prevalence of PCOS in women 18-25 years of age, conducted in college girls from Lucknow, North India. Materials and Methods: Sample size for the study was calculated as 1052. Girls from 3 different colleges were approached (n = 2150), 1520 (70.7%) agreed to participate. They were asked to fill up a questionnaire asking details of menstrual cycle and features of hyperandrogenism. Hirsutism was self-reported. Responses were verified by a trained research assistant. A probable case was defined as a girl with menstrual irregularity (MI) or hirsutism (H) or both. All the probable cases were invited for detailed examination, hormone estimation, and ovarian ultrasonography. Results: Of the 1520 girls, 200 (13.1%) were labeled as probable cases; 175 (87.5%) had MI and 25 (12.5%) had both MI and H. Of the 200 cases, 75 (37.5%) had hormonal evaluation while 11 agreed for ultrasonography. 27 girls had confirmed PCOS. Therefore, if all the 200 girls would have had hormonal evaluation, 56 girls were likely to be confirmed as PCOS, giving a calculated prevalence of 3.7% (95% CI, 2.6-4.4) in this population. The mean age of these PCOS cases was 18.96 ± 1.73 yrs, body mass index was 21.72 ± 5.48 Kg/m 2 , and waist hip ratio was 0.81 ± 0.08. Only 12% girls had a body mass index ≥ 27.5 Kg/m 2 , but 44% had waist hip ratio > 0.81, again highlighting that despite low BMI, Indians have more abdominal obesity. Conclusion: Calculated prevalence of PCOS in women between the ages of 18-25 years from Lucknow, north India, is 3.7%. Majority of these girls were lean but have abdominal obesity.