This study compared the personality characteristics of successful, moderately successful, and unsuccessful high school basketball coaches. Winning percentage was the criterion chosen to measure success. The subjects were 52 varsity high school basketball coaches from Anna Arundel, Baltimore, Montgomery and Prince Georges Counties public schools. Each coach was administered individually the Cattell Sixteen Personality Factor Questionnaire Form A at their respective schools. The coaches were grouped into highly successful, moderately successful, and unsuccessful categories according to their cumulative winning percentage in their last three years of varsity high school basketball coaching. To be highly successful, the coaches needed a winning percentage of .60 or greater, for moderately successful .41-.59, and for unsuccessful .40 or lass. A one-way analysis of variance was computed to determine if any significant differences existed between the three groups on any of the twenty personality factors measured. The results indicated that there are no significant differences on any of the twenty personality factors measured for the three groups. Within the limitations of this study, it would appear reasonable to conclude that there is no difference between the personalities of the highly successful, moderately successful, or the unsuccessful coaches.