This study delves into the intricate relationship among peace attitudes, personality traits, and sustainable behaviors in a diverse sample of 279 adults from different regions of Italy. Building upon the existing literature, this research affirms the influence of agreeableness, openness, and conscientiousness as primary personality traits associated with sustainable behaviors. Additionally, this study scrutinizes the unique predictive power of peace attitudes. The Peace Attitude Scale (PAS), the Big Five Questionnaire (BFQ), and the Sustainable Behaviors Scale (SBS) were utilized to evaluate peace attitudes, personality traits, and sustainable behaviors. The analysis reveals that peace attitudes significantly predict sustainable behaviors, accounting for 31% of the variance. This predictability is attributed to intrinsic motivation and value alignment. Importantly, peace attitudes extend beyond environmental concerns to embrace social justice and equity, integral components of sustainability. The findings underscore the unique and substantial contribution of peace attitudes to understanding sustainable behavior. This study not only confirms the role of personality traits but also emphasizes the importance of intrinsic values in propelling pro-environmental actions.