Objective: To assess the understanding and attitudes of Brazilian men regarding premenstrual syndrome (PMS). Methods: In a survey-based study between September 2007 and April 2008, information was collected from men aged 18-40 years who were attending public healthcare services or were university and faculty staff at 5 cities in different geographic regions of Brazil and the Federal District. Results: In total, 527 men were interviewed. Of these, 863% had heard of PMS, and 343% reported that it is a natural part of the menstrual cycle. The most commonly reported characteristics of PMS were emotional symptoms (55.2%), including nervousness or anxiety; irritability, anger, or aggressiveness; and a greater tendency to start arguments and fights. A significant relationship was found between men who had heard of PMS and being aged 20-35 years, having a university degree, being white, and belonging to a higher socioeconomic stratum (P<0.001). Furthermore, men with a university degree were more likely to know that PMS symptoms occur before menses (P<0.004). Conclusion: Many of the men interviewed were knowledgeable about PMS symptoms; however, this awareness was more common among men of higher socioeconomic strata with more years of schooling. (C) 2012 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.12113134Bayer, Brazil