The prevalence of alexithymia and its association with sociodemographic variables were studied in a sample of 1285 subjects representing the general population of Finland. Alexithymia was measured with the 20-item Toronto Alexithymia Scale (TAS-20). Alexithymia was normally distributed in the population in both genders, confirming that it is a personality dimension. The prevalence of alexithymia was 13%. Men were alexithymic almost twice (17%) as often as women (10%). Multivariate analysis showed that alexithymia was associated with male gender, advanced age, low educational level, and low socioeconomic status. As to the three factors of the TAS-20, men scored higher in factors 2 (difficulty in describing feelings) and 3 (externally oriented thinking). but there was no gender difference in factor 1 (difficulty in identifying feelings). Comparative population studies in other countries are needed to find out whether there are any differences in the prevalence of alexithymia between cultures.