This paper reviews the results of three investigations of the effects of marathon Gestalt workshops on the measured self-actualization of volunteer, college student participants. In the first study, 10 students participated in a weekend workshop at the university counseling center. Subjects completed the Personal Orientation Inventory (POI) before the workshop and again four days later. Significant positive pre-post changes in mean scores were observed on seven of twelve POI scales for the experimental group. A nontreatment group controlled for sex, age, and college class demonstrated no significant changes. In Study II, 36 college student volunteers were randomly assigned by sex to experimental and control conditions. The experimental group participated in a continuous 24-hour Gestalt workshop and completed the POI before, four days after, and six months after the workshop. Findings revealed significant positive pre-post changes on 11 of 12 POI scales. Posttest-followup comparisons indicated that these changes persisted over time and that additional gain was achieved on several POI scales. No significant differences were observed in control group mean scores for pre- and posttests. Study III was a replication of the second study with an increased number of subjects, and the results were highly similar to those in Study II. Results of these three studies suggest that marathon Gestalt workshops appear to foster increased self-actualization in volunteer college students. Suggestions are offered for future research. (Author)