The purpose of this study was to test the relative efficacy of four relaxation techniques (music listening skills, progressive muscle relaxation (PMR), EMG biofeedback and EMG facilitated PMR) in reducing tension levels of internally or externally controlled individuals who were experimentally exposed to a psychosocial stressor. The study utilized 81 college aged males randomly assigned to one of four relaxation training groups or to a control group based on their locus of control - (Rotter's I-E Scale). EMG pre-training baseline measurements were taken via an ASI A1700 and all training groups were given seven 20 minute relaxation training sessions. Three days later each subject was exposed to the six repetitions of a 92 second segment of It Didn't Have to Happen (an industrial accident film). Baseline EMG levels were obtained prior to and following the exposure to the stressor. Data was also collected during the six repetitions. STAI (state) and MAACL (today form) were administered before, after the second exposure to the film and following the post stressor relaxation period. The results of the statistical analyses indicated that the film was able to elevate EMG levels, that biofeedback training produced significantly lower EMG levels during a resting period than music or PMR training, that externally controlled subjects trained with biofeedback reduced their resting EMC levels more than their internal counterparts, that externally controlled individuals trained with biofeedback reduced their EMG levels at a faster rate than internals and that initial muscle tension during exposure to the stressor seemed to be uneffected by the type of relaxation training the subject received or whether he received training at all.