AIMS: Health problems associated with indoor environments have been reported and discussed extensively during the past few decades, not least in Sweden. There is, however, great uncertainty concerning the background prevalence of the symptoms in question. The main objective of the present study was to investigate the prevalence of general, mucosal, and skin symptoms in the Swedish population. METHODS: A survey comprising 3,000 randomly selected Swedes, age 18-64, was carried out. The survey addressed 25 symptoms, principally general, mucosal, and skin symptoms. A number of other areas were covered and individual data registered at Statistics Sweden were added. The response rate was 70% (2,154 cases). RESULTS: The prevalence of symptoms in the Swedish population was found to accord with results in studies based on different kinds of samples. Women reported significantly more single symptoms, as well as sets of symptoms, than men. There was no clear connection between age and symptoms. The prevalence of symptoms was slightly lower among employees compared with non-workers. Office workers did not report symptoms related to "sick building syndrome" (SBS) more frequently than employees not working in offices. SBS symptoms, skin symptoms, and symptoms similar to those reported by individuals with "electric hypersensitivity" were significantly more prevalent among employees with extensive VDU usage. CONCLUSIONS: The prevalence of reported health complaints accords with that which has been found in previous studies. The background prevalence reported here can serve as a reference for further studies. The high prevalence of symptoms among individuals with extensive VDU usage gives cause for further studies.