Objective: To investigate the frequency of premenstrual syndrome (PMS) associated symptoms and effects of nutrition on PMS in adolescent girls. Patients and methods: One hundred and seventy-one adolescent girls who had menstrual cycles were included in this study. They were given a questionnaire on criteria for PMS, dysmenorrhea and regularity of menstrual cycle. Modified Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) criteria were used for the diagnosis of PMS. We also investigated which nutritional supplements affect the PMS-associated symptoms and signs. Results: One hundred and five adolescent girls out of 171 (61.4%) met DSM-IV criteria for PMS. There was an association between dysmenorrhea and PMS in 60 (57.1%). Half of the girls, i.e. 52 (49.5%) had mild, 39 (37.1%) had moderate and 14 (13.4%) had severe PMS. The most common symptom of PMS was negative affect particularly in the form of stress (87.6%) and nervousness (87.6%). There was a statistically significant negative relationship between milk consumption and the following: abdominal bloating, cramps, craving for some foods and increased appetite. Conclusion: PMS and dysmenorrhea are frequently overlapping. We also found that PMS is associated with dietary habits. (C) 2004 Elsevier Ireland Ltd. All rights reserved.