In this study the effects of a worksite stress management intervention on changes in coping styles were examined. Ninety-five participants were randomly assigned to an experimental group participating in the intervention or to a control group with a delayed intervention. The stress management intervention was structured on enhancing so-called positive coping styles focused on problem solving and social diversion and on decreasing negative-emotion-focused and distraction-coping. The results showed that in the experimental group the level of positive coping styles significantly increased. The effect of decreased negative coping styles due to the intervention was observed only in the group of participants with a high level of negative affectivity.