This paper explores models and measurements of psychological androgyny by extending research to a new cultural context-Singapore. Five studies, which include the construction of a culturally appropriate measurement of masculinity and femininity and the investigation of the masculine, additive, and interactive models of psychological androgyny, are reported. The results indicate that the Singapore Androgyny Inventory (SAI) demonstrated good internal consistency and temporal stability. M and F scales were unidimensional and orthogonal with composite items reflecting instrumental and expressive orientations. Masculinity was associated with need for achievement (r = .56), and feminity related to need for affiliation (r = .24). In addition, a 2 (gender) x 2 (M) x 2 (F) analysis of variance revealed main effects for both masculinity and femininity on personal and social self-concept, but no significant interaction effects. The same analysis demonstrated main effects only for masculinity on psychological well-being and self-acceptance. Taken together, evidence supported a differentiated additive model rather than a masculine or interactive model of androgyny, self-concept, and mental health. The advantages of cross-cultural extensions in psychological androgyny research are also discussed.