In planning a longitudinal study to characterize the natural history of benign prostatic hyperplasia (BPH), we validated a new disease-specific quality of life questionnaire in a pilot study. We studied 110 men in Rochester, Minnesota who spanned the severity of BPH, from men with no known BPH to men who underwent surgery for this condition. Baseline data were obtained on all men, and the 30 who underwent prostatectomy were re-interviewed to test responsiveness. Reproducibility was examined on the pre-post responses (10 weeks apart) of the 37 men with BPH who did not undergo prostatectomy. Six of twelve question domains were retained in the final questionnaire on the basis of their responsiveness to change, reproducibility, internal consistency, and validity. These were: urinary symptoms, degree of bother due to urinary symptoms, BPH-specific interference with activities, general psychological well-being, worries and concerns, and sexual satisfaction. Most of the more generic measures were deleted.