OBJECTIVE: Results of past studies of menopause and weight are inconsistent, in part because of problems in study design and analyses, such as retrospective assessment of age at menopause and failure to control for confounding factors. To address such shortcomings, we conducted multivariate analyses on longitudinal data from a large, community-based sample of initially pre- and perimenopausal women who were making the transition through menopause. DESIGN: Data were from the second phase of the Massachusetts Women's Health Study, a cohort of 418 women aged 50-60 years in 1986. We assessed the relationship between menopause transition and weight, after accounting for previous weight; age; and the behavioral factors of smoking, exercise, and annual ethanol consumption. Menopause status was defined in terms of months of amenorrhea. The association of hormone replacement therapy and weight also was examined. RESULTS: Menopause transition was not consistently associated with increased weight, and use of hormone replacement therapy was not significantly related to weight. Behavioral factors--particularly exercise and ethanol consumption--were more strongly related to weight than was menopause transition. CONCLUSIONS: These results are consistent with findings from other studies that suggest that the weight increases experienced by middle-aged women in the United States are not a result of the menopause transition.