© 2020, Springer Nature B.V. The present article aimed to elaborate the Prosocial Personality Inventory (PSPI+), gathering evidence of its validity (factorial and criterion) and reliability. Six traits were hypothesized, grouped into three first-order factors: altruism (beneficence and egotism), forgiveness (remission and incrimination), and gratitude (recognition and inexpressiveness). Two studies were carried out (n = 1033). This factor structure was identified in Study 1 and confirmed in Study 2. Overall, all factors presented Cronbach’s alpha of.70 or higher. Systematically, positive and negative aspects of prosocial traits were correlated with agreeableness and dark traits. Moreover, such bright traits were positively correlated with self-reported pro-social behavior. In conclusion, the PSPI+ is a short, theoretically and psychometrically sounds instrument for measuring prosocial personality (altruism, forgiveness, and gratitude), useful for studies focusing on correlates of bright personality (e.g., well-being, voluntarism).