Diversity management has been expected not only to progress productive nursing service, but also to promote well-being among Japanese nurses. However, Japanese conventional studies have not shown enough statistical evidences. Hence, this study examined the relationship between perception of workforce diversity and mental health condition among Japanese nurses. Through the internet research, we collected a total of 1,031 valid data (male = 217, female = 814). This study constructed eighteen original items to assess the acceptance levels of diversity elements; seniority, managerial position, clinical experience, employment history, academic background, generation, gender, nationality, role orientation, employment pattern, license, personality, health condition, family situation, work and life priorities, hometown, nursing ability and work motivation. Each diversity element was evaluated by four acceptance levels; (1) refusing diversity (Resistance), (2) ignoring diversity (Assimilation), (3) valuing diversity (Separation) and (4) utilizing diversity (Integration). Mental health condition was assessed by the 12-item General Health Questionnaire (GHQ-12, high-stress ≧6 point). As the results of a logistic regression analysis, higher acceptance of the managerial position, personality and work and life priorities were negatively related with high-stress. Higher acceptance of the employment pattern and work motivation were positively related with high-stress. These results indicated that diversity management was one of the effective approaches to improve mental health condition among Japanese working nurses.