The purpose of this study was to determine the effectiveness of self-selected versus investigator-assigned mantras on physiologic responses to breathing meditation. Subjects (21 ± 3.4 yrs.) included 8 females and 4 males, all of whom were novice meditators. After orientation and informed consent, subjects were randomly assigned to one of two experimental groups. One group (SS) was asked to think of a word or short phrase of deep personal significance that would be effective in producing relaxation and to repeat this mantra on each exhalation. The other group (IA) was simply told to repeat “one” on each exhalation. All subjects sat in the same chair in the same dimly lit, thermoneutral room throughout the ten minute meditation period. All subjects closed their eyes for the duration of the experiment. The same investigator took all physiologic measures and was the only other person in the room during the experiment. At baseline, after 5 min and after 10 min of meditation, subjects’ blood pressure (BP) was assessed using an aneroid sphygmomanometer, finger temperature was assessed electronically (Autogenic Systems AT42), heart rate (HR) was assessed using Polar monitor, and respiratory rate (RR) was assessed by visual observation by a trained EMT. A repeated measures ANOVA was used to compare the physiologic responses between the conditions at different time points. One test was performed for each of the four physiologic variables. No significant differences (p>.05) were revealed for any physiologic measures at any time point. RR did tend to be lower during SS (9.17 ± 3.13 vs. 12.83 ± 5.38 br/min) at 10 min. These results reinforce the notion that physiologic relaxation can be achieved without the use of a specialized mantra during meditative practice. However, longer practice durations and better trained subjects may reveal different results. Keyword(s): interdisciplinary, measurement/evaluation, wellness/disease prevention