Work-related stress (of which burnout might be an example) is one of the most common work-related health problems. Currently, psychiatric illness (particularly depression, anxiety disorders, and stress related conditions) is the most common cause for long-term sick-leave in Sweden for women, and the second largest for men. Finding adequate strategies to prevent stress and burnout therefore seems important. This thesis is based on a questionnaire survey among all employees in a Swedish County Council. The overall response rate was 65% (n = 3976). The aims of the thesis were to: (1) Investigate how four burnout categories (non-burnout, disengaged, exhausted, and burnout) are linked to constellations of work characteristics, including self-reported sickness absence, sickness presence and overtime. (2) Test the Job Demand-Resources model in a sample of Swedish healthcare workers. (3) Investigate how burnout relates to self-reported physical and mental health, sleep disturbance, memory and lifestyle factors. (4) Test the effect of participating in a reflecting peer-support group on self-reported health, burnout, and on perceived changes in work conditions. (5) Investigate the factorial structure of the Swedish translation of the Oldenburg Burnout Inventory, and its predictive validity on future long-term sickness absence. Results revealed that burnout is associated with poorer self-rated health, more depression and anxiety, overtime work, and with future long-term sickness absence as measured by register data. Burnout as a possible pathway to an exhaustion disorder is discussed. Contrary to the general belief, that job demands make all the difference, results indicated that it was the access to/lack of adequate job resources that determined whether an employee was classified as burnt out or not. Additional support for the Job Demands-Resources model was found, insofar that job demands were more closely related to exhaustion, while lack of job resources was more associated with disengagement. Reflecting peer-support groups, using a problem-based method, was tested in a randomized controlled trial, and showed positive intervention effects in self-reported health, participation and development opportunities at work, support at work, and in work demands. Based on the result in this thesis, a fair and empowering leadership, a positive social climate at work, control of decision, and support from superiors, as well as a reasonable work load appear to be important factors in the prevention of burnout. Reflecting peer-support groups using a problem-based method could be a useful and comparatively inexpensive tool in alleviating work-related stress and burnout. Further research is needed, before any conclusions about the usefulness of the method for men can be drawn.