A comprehensive methodology for the measurement of stress comprises objective physiological and biochemical methods as well as application of self-reporting scales. This overview focuses on the subjective procedures, their psycho-physiological theoretical background and practical issues. We discuss the most valuable procedures used to assess stress factors, reactions to stress and relationships between the stressed subject and the physical and psychosocial environment. The strengths and limitations of self-reports and the conditions to obtain reliable data and to interpret the findings are outlined. The results of several investigations performed by our teams concern especially the assessment of occupational stress.