Objectives: This study was undertaken to examine the association between sickness absence in Japanese employees and job demand/control and occupational class as psychosocial work characteristics. Methods: The s tudy was cross-sectional in design with data collected from 20,464 male and 3,617 female employees, whose mean age was 40.9 years (SD ± 9.1 years) and 36.9 years (SD ± 10.8 years), respectively. The participants were asked to write the total number of sick leaves they had taken during the past year, and a comparison was made between the group with more than 6 days of sickness absence and the group with 0-6 days as a reference group. Job demands, job control, and worksite support from supervisors and colleagues were analyzed by the Job Content Questionnaire, and likewise by the Generic Job Stress Questionnaire of the National Institute for Occupational Safety and Health. Results: Both low job control and low s upport at the worksite were associated with a high frequency of sickness absence. But there was no clear relationship between job demands and sickness absence. The lowest sickness absence rate was found in male managers and the highest in male and female laborers. Conclusion: This is the first report of a large-sc ale survey of Japanese employees to show a high frequency of sickness absence associated with increased work stress and a socioeconomically low occupational class. © Springer-Verlag 2006.