Aims: To investigate the longitudinal relation between strenuous leisure time physical activity and psychological complaints (depression and emotional exhaustion) in a Dutch working population in order to find evidence For the preventive role of physical activity in the development of psychological complaints. Methods: All data came from the Study on Musculoskeletal disorders, Absenteeism, Stress, and Health (SMASH), a three year follow up study that started between 1994 and 1995. The study population consisted of 1747 workers from 34 companies. Generalised estimating equation (GEE) analyses were performed to investigate the longitudinal relation between strenuous leisure time physical activity and psychological complaints using models with and without a time lag. Logistic regression analyses were performed to study the relation between physical activity and sickness absence due to psychological complaints during the three year follow up study. Results: Only in workers with a sedentary job was strenuous leisure time physical activity (1-2 times per week) significantly associated with a reduced risk of future depression and emotional exhaustion. This was not the case for physical activity at higher frequencies (≥ 3 times per week). There was a dose-response relation between strenuous leisure time physical activity and poor general health which was strongest in workers with a sedentary job. Strenuous leisure time physical activity (1-2 times per week) was associated with a lower risk of long term absenteeism (> 21 days), whereas physical activity at a higher frequency was not. Conclusions: Results suggest that strenuous leisure time physical activity might play a role in the prevention of future psychological complaints, poor general health, and long term absenteeism in a working population. Workers with a sedentary job seem to benefit more from strenuous leisure time physical activity than workers without a sedentary job.