AIM: The aim of this study was to explore the prevalence of dizziness in a general population and the association between dizziness and socio-demographic variables, self-reported diseases and medicines used. We hypothesize that dizziness was associated with different diseases and medicines as well as the number of diseases and the number of medicines used. MATERIALS AND METHODS: We used data from a cross-sectional survey with 17,638 participants aged 30, 40, 45, 59/60 and 75/76 in the Oslo Health Study who had answered a self-administered questionnaire in 2000-2001. Associations were analyzed by descriptive statistics, chi-square tests, independent t-tests and logistic regression. RESULTS: The prevalence of self-reported faintness or dizziness was 28.7%, reported more often by women than men and by age group 75/76. Participants with neck shoulder pain/stiffness, mental disorders, fibromyalgia/chronic pain syndrome, stroke/cerebral haemorrhage, angina pectoris and chronic bronchitis/emphysema, as well as use of tranquillizers, sedatives, and ''other medicines on prescription,'' had a significantly increased likelihood of being troubled by faintness or dizziness. An increasing number of reported diseases and an increasing number of medicines used gave an increasing likelihood of faintness or dizziness. In the multivariate analysis controlling for socio-demographic variables, diseases and use of medicines, the oldest did not have an increased likelihood of faintness or dizziness. CONCLUSIONS: Self-reported diseases and medicines used could explain a modest rise in the prevalence of faintness or dizziness by age. Sum of diseases and sum of medicines used were associated with reporting dizziness to a greater extent than the different diseases and medicines used.