Physiological indices of stress were found to be lower in people who regularly practiced Transcendental Meditation (N=14) than in nonmeditating control subjects (N=16). During normal waking (eyes open) a noxious loud tone (100 db, 0.5 sec, 3000 Hz) was presented to subjects a mean of once every 53 sec at irregular intervals. The stress reaction to each tone, as indicated by the galvanic skin response (GSR), was compared for the two groups. Habituation of the GSR to tones was faster for meditators than for controls, and meditators made fewer multiple responses during habituation, indicating greater stability in response to stress. In two other experiments, meditators were found to make fewer spontaneous GSR's than control subjects, both during meditation, as compared with rest (eyes closed), and while out of meditation with eyes open. Thus meditators were found to be more stable than controls on three autonomic indices: rate of GSR habituation, multiple responses, and spontaneous GSR.