The prevalence of abdominal symptoms was studied by means of a postal questionnaire sent to a representative sample (n = 1290) of the adult population of a Swedish municipality. The subjects were asked about the occurrence of 35 abdominal symptoms during the preceding 3 months. The participation rate was 89.6%, and 54.3% of the responders reported at least one discomforting abdominal symptom. The overall prevalence rate was significantly higher in women than in men, and the highest rate (75%) was found among young women. The average number of symptoms per individual was also significantly higher in women. The overall prevalence rate in women decreased significantly with age, irrespective of menopause. The prevalence of most individual symptoms decreased with age and/or was higher in women. However, the prevalence of symptoms indicative of gastro-oesophageal reflux disease did not vary with age or sex. The prevalence of symptoms usually regarded as ominous did not increase with age; in some instances it even decreased. With the exception of reflux symptoms and night pain, the apparent disappearance with increasing age implies that most of the complaints are of functional origin.