This study developed a Japanese version of the Machiavellianism scale (Mach IV) and examined its reliability and validity. A questionnaire survey of university, junior college and vocational school students showed sufficient internal consistency and test-retest reliability for the scale. Its correlational validity was demonstrated in terms of the relationships with psychopathic tendencies, prosocial behavior, and Agreeableness (a dimension of the Five-Factor personality model). These results indicated that the Japanese version of the Machiavellian scale IV is useful to measure Machiavellian tendencies.