The purpose of this paper is to review those studies related to the clinical applications of perceived exertion. The Borg Scale has been used most widely to evaluate the subjective response of patients during graded exercise tests. More recently, ratings of perceived exertion (RPE) have been shown to be an accurate predictor of aerobic capacity. Appraisal of angina pectoris during exercise is discussed relative to its interaction with effort perceptions. Two groups of investigators have recently studied the validity of using stress-test perceptions to control exercise intensity during training. Caution is suggested when perceptual prescriptions are based upon estimation techniques in exercise tests but require production techniques by patients in exercise programs. One investigation was reviewed to illustrate the use of perceptual information in solving occupational problems: three lifting techniques were compared relative to perceptual acceptability, the recommended squat technique being the least acceptable. A variety of sport applications were discussed: perception of pace, sex differences in perception of effort, perceptual recovery from exercise, and the new Borg Category-Ratio Scale in the measurement of anaerobic stress and several recommendations were made for future study of clinical applications of perceived exertion.