Premenstrual dysphoric disorder (PMDD) is a severe form of premenstrual syndrome (PMS) that is predominantly characterized by mood symptoms, and debilitating physical and cognitive symptoms, which have a direct or indirect impact on work efficiency, social and personal relationships, and overall quality of life. This study was conducted to determine the prevalence of moderate to severe PMS and PMDD among young women in India and investigate sociodemographic and other associated factors. We conducted a cross-sectional study that included 198 young women between 17 and 30 years of age who were medical students or nursing staff from a medical college in Eastern India. Data were collected regarding sociodemographic information, menstrual patterns, age of menarche, sexually active status, body mass index, and level of physical activity, which were analyzed to find correlations with moderate to severe PMS or PMDD. The Premenstrual Symptoms Screening Tool was used for diagnosing moderate to severe PMS or PMDD. The data were analyzed using Statistical Product and Service Solutions (SPSS, version 24.0; IBM SPSS Statistics for Windows, Armonk, NY) software. Forty-six (23.5%) respondents were diagnosed with moderate-to-severe PMS, of which four (2%) were diagnosed with PMDD. Among those diagnosed with moderate-to-severe PMS/PMDD, 39 (27.3%) were of the age group 17-24 years, and seven (13.2%) were of the age group 25-30 years, which was a statistically significant difference (p=0.05). Thirty-eight (30.6%) students were diagnosed with moderate-to-severe PMS, as compared to eight (11.1%) working professionals, which was also a statistically significant difference. Moderate-to-severe PMS significantly impacts quality of life. Considering its prevalence among young subjects, it is important to make young girls aware of the condition and educate them regarding various ways to manage their symptoms.