This article provides an overview of information on the prevalence of perimenstrual symptoms. Overall, at least 40% of women experience some cyclical perimenstrual symptoms. Although most women rate their symptoms as mild, approximately 2%-10% report severe symptoms. Prospective studies of perimenstrual symptoms indicate that retrospective reports are reasonably accurate among women who experience moderate to severe symptoms. However, among the majority of women with few or minimal symptoms, retrospective reports may amplify the cyclicity of variation in comparison to concurrent reports. A variety of risk factors are associated with patterns of symptom reporting and may provide clues to the etiology of perimenstrual symptoms and help to identify women most vulnerable to them. A woman's age and cycle characteristics are predictors of the type and severity of perimenstrual symptoms she experiences. In addition, a history of affective illness may be associated with increased reporting of perimenstrual symptoms. Future research should focus on developing new diagnostic criteria for subtypes of perimenstrual syndromes, exploring positive symptoms and experiences associated with the menstrual cycle, and formulating holistic treatment approaches that view perimenstrual syndromes as psychosomatic conditions.