ABSTRACT: Psychogenic fever is one of the most common psychosomatic diseases. In Japan, psychogenic fever has generally been reported to occur in adolescents, with a peak seen at age 13. However, in our department we have encountered many adults with psychogenic fever. Therefore, we investigated all outpatients who visited the Psychosomatic Department of the University of Occupational and Environmental Health between April 2003 and March 2007. Of the 2705 outpatients that were seen, 55 patients (2.0%) were diagnosed with psychogenic fever. The patients ranged in age from 11 to 82 years old, with a mean age of 33.6 +/- 17.9 (mean +/- SD) years. In addition to the adolescents, many of the patients were in their 20 s and 30 s, and the male:female ratio was 1:2.2. This study suggests that psychogenic fever commonly occurs not only in adolescents but also in adults.