Gender differences in adolescent interpersonal identity formation were investigated in 41 male and 42 female high school juniors and seniors. Subjects were interviewed and assessed on progress toward interpersonal identity achievement in friendship and dating relationships. Differential patterns of correlation for each sex were examined for measures of vocational identity, psychological masculinity and femininity, and achievement motivation. Results indicated that young women were significantly more identity achieved than men in the friendship domain; no differences emerged in the dating domain. The processes of interpersonal and vocational identity formation appeared to be more interrelated for females than males. For both young men and women, expressive attributes of psychological femininity were positively related to interpersonal identity exploration. Different gender achievement orientations were revealed by positive correlations between several interpersonal identity ratings and mastery for males and lack of correlation between interpersonal identity and mastery for females. In addition, commitment to a conception regarding friendships was positively correlated with competitiveness for males and negatively correlated with competitiveness for females. Results are discussed in terms of Gilligan's (1982) theoretical work, which contrasts achievement of identity through separateness and autonomy with achievement of identity through connectedness and relationships.