Background: The mechanisms causing postmenopausal vasomotor symptoms are unknown, but changes in hypothalamic beta-endorphins have been suggested to be involved. beta-endorphin production may be increased by regular physical exercise. Objective: To assess if physically active women suffered from vasomotor symptoms to a lower extent than sedentary women. Material and methods: All women (n = 1323) in the ages ranging from 55-56 years in the community of Linkoping Sweden, were included. In a questionnaire these women were asked about their physical exercise habits and their complaints from vasomotor symptoms. Only those 793 women who had reached a natural menopause were grouped into sedentary, moderately or highly active women, based on a physical activity score. Results: Only 5% of highly physically active women experienced severe hot flushes as compared with 14-16% of women who had little or no weekly exercise (P less than 0.05; relative risk 0.26; CI 95%: 0.10-0.71). This was not explained by differences in body mass index, smoking habits or use of hormone replacement therapy. Women who used hormone replacement therapy were more physically active than non-users (P less than 0.05). Conclusion: Fewer physically active women had severe vasomotor symptoms compared with sedentary women. This may be due to a selection bias but also to the fact that physical exercise on a regular basis affects neurotransmitters which regulate central thermoregulation.