Rising rates of heterosexually transmitted HIV among youth and young adults, particularly from ethnic minorities, create an urgent need to understand risk factors and perceptions of risk within the context of couple relationships. This study examined reports of young mothers and fathers (predominantly Latino) about background characteristics, relationship quality and length, HIV-related risk factors, and perceptions of partners' behaviors and personal history. Higher concordance was found for relationship characteristics and partners' personal history (e.g., incarceration) than on shared sexual behaviors. Most males and females stated that they were monogamous; however, those whose partners reported concurrency were unaware of this. Many were unaware of their partners' HIV testing status. Relationship quality was higher when females accurately perceived their partners' self-reported HIV-related risk behaviors. Length of the relationship did not influence concordance. Findings support the need for HIV prevention programs to promote open discussion about condom use and HIV testing within sexual partnerships.