The relationship of psychoticism, extraversion-introversion, and neuroticism to the practice of Transcendental Meditation was studied. Male meditators (n = 39) were more introverted and more neurotic than the normal population, whereas the female meditators (n = 27) had a higher mean psychoticism score. Over a 6-mo. period of meditation, the males (n = 24) became less neurotic; the degree to which they did so was related to the frequency of meditation. The implications of these findings are discussed.