Changes in body image across the menstrual cycle and the relationship between these changes and menstrual distress were investigated in an effort to identify determinants of body dissatisfaction. Twenty-six normally cycling women between 18–40 years of age and 90–115% of ideal body weight, with no history of an eating disorder, completed a series of body image measures and a measure of menstrual distress during three menstrual cycle phases: perimenstrual, follicular, and luteal. These phases were identified with serum levels of ovarian hormones and basal body temperature. Results indicated that body dissatisfaction as measured by the number of body-related negative thoughts and anxiety about appearance was significantly highest during the perimenstrual phase. In contrast, measures of body size perception remained stable. Several somatosensory and psychological symptoms of menstrual distress were significantly associated with body dissatisfaction during the perimenstrual phase including, water retention, autonomic reactivity, control, negative affect, and impaired concentration. This association of body dissatisfaction and menstrual distress strongly suggests that menstrual cycle changes play a significant role in body image. © 1994 by John Wiley & Sons, Inc.