Just prior to engaging in actual sales activities, 41 prospective car salesmen underwent the Diamond Personality Inventory which consisted of 14 personality scales-Aggressiveness, Cooperativeness, Deliberateness, Perseverance, Creative attitude, Moralisticness, Emotional stability, Submissiveness, and Independence. Three criteria of sales success were used-the total number of cars sold during 18-month, 30-month, and 42-month periods. Results obtained from correlational analyses between the 14 personality trait predictors and the three criteria revealed that six personality valiables in the Diamond Personality Inventory-Aggressiveness, Self-confidence, Leadership, Empathy, Vigorousness, and Independence were correlated significantly with the three criteria of sales success.