Statistics and prescription database studies show that analgesics are widely utilized, but do not tell anything about either the factors behind analgesic use or how over-the-counter (OTC) analgesics are being used. We aimed to study the prevalence of frequent use of prescribed and OTC analgesics. We also investigated the background factors related to frequent analgesic use and assessed rationality of analgesic usage patterns. We addressed a postal survey to a random stratified population sample of 6500 Finnish people aged 15-74 years. The response rate was 71% (n=4542) after exclusion of unobtainable addressees (n=68). Individuals reporting analgesic use 'daily' or 'a few times a week' were categorized as frequent users. After adjusting for age and sex, the overall prevalence of daily analgesic use was 8.5%, and the prevalence of analgesic use a few times a week 13.6%. The adjusted prevalence of using exclusively prescribed analgesics daily or a few times a week was 8.7%, and that of utilizing purely OTC analgesics 8.8%. The overall prevalence of concomitant frequent use of both prescribed and OTC analgesics was 4.6%. Multinominal logistic regression analyses showed that frequent analgesic use was related especially to daily or continuous pain and high pain intensity. Low mood and not being employed also increased the probability for daily analgesic use. Frequent analgesic use seems to be common at population level. Concomitant use of both prescribed and OTC analgesics can be considered irrational, as it increases the risk of adverse events.