Aim: To examine the association of serum anti-Müllerian hormone (AMH) levels with biochemical derangement and sonographic appearance in PCOS women and to examine its role as a possible marker for diagnosis and prognosis of polycystic ovarian syndrome (PCOS). Materials and methods: This case-control study was conducted on patients attending the Gynecology OPD at ESIC Medical College and Hospital, Faridabad, Haryana from March 2017 to September 2017. 45 PCOS women and controls between 18 years and 45 years were recruited. Relevant clinical, biochemical, and sonographic data were collected. Linear regression was used to study the association between biochemical and sonographic variables and PCOS. Receiver-operating characteristic (ROC) curve analysis was performed for AMH, LH/FSH ratio, antral follicle count (AFC), and mean ovarian volume. The AMH cut-off value was determined for the prediction of PCOS. Results: Mean AMH levels were significantly higher in the PCOS group (5.9 v/s 2.36 ng/mL). In PCOS women, AMH levels positively correlated with AFC, mean ovarian volume, as well as androstenedione and testosterone levels. In controls, a significant positive correlation was found with serum testosterone and mean ovarian volume. An AMH had greater diagnostic potential for detecting PCOS compared to AFC, mean ovarian volume, and LH/FSH ratio. A threshold AMH value of 3.98 ng/mL had a sensitivity of 82.2% and a specificity of 93.3% for diagnosing PCOS. Conclusion: Serum AMH levels correlate well with hyperandrogenemia and sonographic features of PCOS and could be used as a marker for hormonal dysfunction and disease severity. Clinical significance: An AMH is a promising marker that could improve the diagnosis of PCOS and also help in establishing disease severity.