The Danish Prostatic Symptom Score (DAN-PSS-1) comprises 12 questions related to voiding problems in benign prostatic hyperplasia. The patient himself scores each symptom as regards severity (symptom score) and impact on daily life (bother score). The precision of this patient-weighted (postal) questionnaire was investigated in terms of repeat frequencies of replies from 197 randomly selected men on two sequential occasions. The questionnaire was well understood by the patients. The median frequency of repeat in answers to the questions was 83.5% (range 0-99.7%). This frequency depended on the nature of the question and the severity or bother of the symptom. Repeatability as regards bother rose markedly when the bother score was made dependent of the symptom score, suggesting a relationship between the two. As with other questionnaires, the precision of those dealing with prostatism should be established before clinical use. The observed relationship between symptom score and bother score may be of diagnostic value.