The purpose of the investigation was to determine the effectiveness of Zen meditation practice in facilitating positive change on the personality variables time competence, inner direction, locus of control, and field independence, as well as to investigate the subjective experiences of novice meditators. Two population groups were included in the study: a student group and a clinical group. The student-population group consisted of forty-six undergraduate college students. The student subjects were randomly assigned to one of three groups: experimental group (Zen meditation group taught to focus attention on the breath, as well as a formal Zen posture), placebo group (formal Zen posture only), or control group (no treatment). The clinical-population group consisted of thirty-seven in-patient volunteers from the alcoholic-drug unit of a psychiatric state hospital. The clinical subjects were randomly assigned to either an experimental group (Zen meditation group which practiced focused attention on the breath, as well as a formal Zen meditation posture) or a control group (no treatment).