Freefall parachuting is a demanding activity which, at times, is profoundly stressful. Fifty-nine freefall parachutists completed a survey which dealt with parachuting experience, levels of perceived stress, sources of stress, episodes of altered consciousness, and use of hypnotic techniques in preparation for freefall. Over one third admitted to having experienced a "trance-like state" before, during, or after a jump; the same was true of a state of "altered consciousness." The great majority used mental imagery or another mental or physical technique to prepare for freefall. These results recall the theory that stress predisposes to hypnotic trance. Trance, when unconsciously evoked during emergencies (spontaneous dissociation), may account for some parachuting accidents. When consciously pursued, however, self-hypnosis may provide the jumper with a way to control his level of arousal, facilitate cognitive rehearsal, and enhance performance.