A total of 77 men with prostatic carcinoma treated with orchiectomy or a gonadotropin releasing hormone analogue before September 1987 underwent evaluation by a questionnaire regarding vasomotor symptoms. Answers were received from 84% of the patients. Of 63 patients 43 (68%) reported hot flushes during treatment, while 30 (48%) still had flushes 5 years after treatment. Of the latter 30 patients 28 (median 7.6 years after treatment) had vasomotor symptoms at the time of the study. Only 13 of 43 men with vasomotor symptoms after the start of treatment had relief 5 years later. At the time of the study 13 of 30 patients (more than 40%) still had flushes 8 years after castration. Most men reported that the flushes presently had the same frequency and duration as when they started therapy. Contrary to the general belief that the symptoms disappear with time, our study highlighted a long persistence of hot flushes after castration.