One fifth of workers reports experiencing stress in the work environment in Europe. A number of studies show that psychosocial stressors in the workplace are associated with adverse physical and mental health outcomes, including symptoms of anxiety and depression. The present paper: briefly describes the characteristics of occupational stress and the main psychosocial stressful risk factors in the work environment; reports the main results of studies on psychosocial risk factors in the work environment as risk factor for common mental disorders; presents findings from an Italian study aimed at assessing prevalence of common mental disorders and workplace psychosocial stressors in a sample of hospital employees; provides the "Working conditions Questionnaire", a validated self-administered instrument to assess perceived stress in the workplace; this questionnaire includes the assessment of organizational justice.