A within-subjects, three condition design was employed to examine the effects of three relaxation techniques on blood pressures, pulse rates, and self-report measures of relaxation for 12 college students. Respiratory Manipulation Training incorporated instructions to exhale and not to inhale for as long as possible. When breathing could no longer be restrained, students inhaled and attended to the relief experienced. Next, two deep-breathing cycles were completed, and then voluntary respiratory arrest was resumed. The respiratory-arrest/deep-breathing sequence was repeated, without rest, for the duration of the technique. Progressive muscle relaxation followed the standard four-major-muscle-group, tension/release procedure. Pleasant imagery involved instructions to develop preselected scenes, while random stimulus and response propositional prompts were offered to enhance imagery. All techniques lasted 15 minutes and were reproduced, via audio cassette, to control for experimenter bias and stimulus variation. Order of technique presentation was counterbalanced, while modified, 5-minute, Stroop effect exercises were utilized to restore students to pretechnique physiological levels. An analysis of the results revealed that Respiratory Manipulation Training reduced systolic and diastolic blood pressures significantly greater than the other two techniques. These results may be due to the combination of relief and relaxation responses inherent in the respiratory manipulation. (Author/BL)