The purpose of this study was to assess the reliability and validity of a single-item measure of Usual Physical Activity and to assess its usefulness as a physical activity tool for perimenopausal women. 188 perimenopausal women participated (age: M = 47 yr., SD = 3; range = 40-55). Data were collected using the Women's Health Assessment Scale, the Physical Activity Questionnaire, the Perimenopause-related Quality of Life Scale, a health history and demographic questionnaire, and the rater. Scores were stable over a 2-wk. interval. Convergent validity was supported by a correlation of .66 between ratings on Usual Physical Activity and the Physical Activity Questionnaire. Concurrent validity was supported by the association of the rating of Usual Physical Activity with three parameters of Body Mass Index, psychosomatic symptoms, and perimenopause related quality of life, known to be associated with physical activity. Highly active women had a lower Body Mass Index than less active and inactive women. Active women tended to report fewer and less distressing psychosomatic symptoms and better quality of life. These findings support the use of rating of Usual Physical Activity to classify perimenopausal women into categories of physical activity.