A telephone survey of a random sample of 594 perimenopausal women was done to study the prevalence of hot flashes, use of estrogen, age of menopause onset, and, among those subjects experiencing hot flashes, the frequency of occurrence and number of years of hot flashes. The prevalence of hot flashes was 88%. Surgical menopause women had a prevalence rate of 92% and had the highest estrogen utilization rate. The median age of onset for natural menopause women was 49 years. The frequency of occurrence and number of years of hot flash experience was variable across all groups.