This essay aims to compare and contrast two of the four stress models; Hans Selye's (1907-1982) general adaptation syndrome (GAS) model and Mowrer's (1939) avoidance model. First, the author will provide published definitions of the term stress; the author will then briefly discuss the term stress. This essay will examine Selye's (1956) general adaptation syndrome and Mowrer's (1939) stress avoidance model and then compare and contrast both models. Chorousos et al. (1988) define stress as “the organism's recognition of a stressor and therefore the state of threatened homeostasis”. Schaffer (2000) defines stress as “the arousal of the mind and body in response to demands made on them. And according to Sapolsky (1994 p7) a stressor is anything that causes the body to lose its homeostatic balance, for example an illness, a loud noise, an injury, etc. Cox (1978 p. 180) defines stress as a “complex and dynamic system of transactions between the person and his environment”. Based on published definitions of stress, the author then defines stress as anything that causes discomfort to the body. Stress can be caused by various factors ranging from physical ones (such as fear of something dangerous) to emotional ones such as worry about children, work, marriage, etc. The term "stress" was coined by the scientist Hans Selye (1907-1982) in 1936. Selye (1926) defined stress as "the non-specific response of the body to any request for change". Selye (1926) discovered in several laboratory experiments that animals showed similar symptoms when exposed to severe physical and emotional stimuli, for example, extreme heat or cold, loud disturbing noises, etc. Selye (1935) also noted that patients with different diseases showed these same similar biological symptoms. symptoms… half of the article… a social, emotional, and physiological approach to stress risk and the development of active behaviors, in J. Stellman (ed.). Encyclopedia of health and safety at work. Geneva: International Labor Office, 34.6-34.14.Lazarus, R. S. & Folkman, S. (1984). Stress, evaluation and coping. New York: Springer. Lazarus, R. S. (1991). Psychological stress in the workplace. In PLPerrewe (ed.). Handbook of occupational stress, Journal of Social Behavior and Personality, 6, 1-13.Mackay C., Cox, T. Burrows, G. Lazzerini (1978). An inventory for measuring self-reported stress and arousal. British Journal of Social and Clinical Psychology, 17, 3, 283-4Welbourne, J. L., Eggerth, D., Hartley, T. A., Andrew, M. E. & Sanchez, F. (2007). Coping strategies in the workplace: Relationships with attributional style and job satisfaction, Journal of Vocational Behavior, 70, 312-325