A detailed questionnaire on the occurrence of irritative and obstructive voiding symptoms, incontinence and the number of childbirths was sent out to 600 women aged between 20 and 79 years, randomly selected from the National Register; 432 (72%) returned the questionnaire and 414 (69%) were evaluable. The frequency of obstructive symptoms such as hesitancy, intermittency and decreased stream was low. Diurnal frequency with voiding intervals less than 3 h were recorded by more than 50% of the women and about 10% voided more frequently than every second hour. Nocturia increased significantly with age; 54 (13.6%) voided at least twice per night. About 40% complained of incontinence but this was troublesome in only 6%; 15.3, 13.3 and 11.5% had stress, urge and mixed incontinence respectively. More than 8% wore nappies or sanitary towels every day to protect against urinary leakage. Although the tendency to wear nappies or sanitary towels increased with age, the increase was not statistically significant. There was a positive correlation between the occurrence of stress incontinence and childbirth in the group as a whole.