Ideal partner traits and how they relate to a young woman’s current partner and relationship is a knowledge gap in the literature. The objectives of this study were 1) to assess any differences in interpersonal characteristics between a young woman or her partner and relationship and 2) to examine the impact of this difference on sexual monogamy, condom use and frequency of vaginal sex. Study participants (n=387, 14–17 years at enrollment, 90% African American) were recruited from three primary care adolescent health clinics serving areas with high rates of unintended pregnancy and sexually transmitted infection (STI); data were drawn from a longitudinal cohort study of sexual relationships and behaviors among young women. Nineteen interpersonal characteristics, including physical, financial, communication and personal characteristic variables, were found to have varying influences on relationships and sexual behaviors with ‘like him’ and ‘like us’ as referents. Monogamy increased as a male partner wanted to get somewhere in life [OR 5.41, (1.25, 23.52, p<0.05)], was intelligent [OR 3.42, (1.09, 10.76, p<0.05)] and had money [OR 1.55, (0.272, 0.595, p<0.001)] in a partnership; monogamy similarly increased when a partner wanted to get somewhere in life [OR 6.77, (1.51, 30.36, p<0.01)], was intelligent [OR 4.02, (1.23, 13.23, p<0.05)], and had money [OR 2.41, (1.51, 3.84, p<0.001)] compared to the young woman. The likelihood of using a condom at last sex increased when the male partner had a nice body [OR 1.42, (1.02, 1.99, p<0.05)], was popular [OR 1.60, (1.12, 2.29, p<0.01)], cared for others [OR 3.43, (1.32, 8.98, p<0.01)], was good at sports [OR 1.35, (1.06, 1.73, p<0.05)] and expressed his feelings [OR 2.03, (1.14, 3.60, p<0.01)]. The condom use ratio increased when the male partner was able to take care of himself [OR 0.076, (0.017, 0.136, p<0.01)], was cute [OR 0.190, (0.082, 0.30, p<0.001)], and had a nice body [OR 0.044, (0.001, 0.09, p<0.05)] in a dyad; the condom use ratio also increased when a male partner could take care of himself [OR 0.091, (0.014, 0.168, p<0.05)], was cute [OR 0.194, (0.077, 0.311, p<0.001)] compared to the young woman. Coital frequency increased when the male partner was described as being able to take care of himself [OR 3.33, (0.138, 6.52, p<0.05)]. Such influences are important in discussions with young women regarding personal and partner choices in sexual health as partners, behaviors and motivations for choice frequently change.