Introduction: Premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD) are premenstrual disorders characterized by a cyclical pattern of severe premenstrual symptoms experienced by women, which typically occurs during the days prior to menstruation and ends at the onset of menses. These symptoms may be unbearable in some women and hinder normal daily life including personal relationships, social activities, work and academic activities. The aim of the present study was to assess the prevalence and severity of PMS among female students. Material and methods: PMS and PMDD were diagnosed using the Calendar of Premenstrual Experiences (COPE) form. Participants were requested to complete the form for two consecutive menstrual cycles. A cross-sectional descriptive study was conducted in 480 female students (aged 15 to 45 years) at the University of Nigeria, Nsukka. Results: Of the 480 participants, 206 (42.9%) women met the criteria for diagnosis of PMS, and 274 (57.1%) did not meet the criteria for PMS. Among participants with PMS, 98 (47.6%) women met the criteria for severe PMS or PMDD. In women with PMS, the most prevalent symptoms were trouble concentrating (85.0%), irritability (79.2%), abdominal bloating (75.3%), aches and pains (70.0%), mood swings (69.2%), breast tenderness (69.2%), and food craving (68.0%). Conclusions: The prevalence of PMS, as well as PMDD, was high among female students in Nigeria.