Young black men who have sex with men (YBMSM) are experiencing high and rising rates of HIV infection, more than any other age-risk group category in the USA. Contributors to HIV risk in this group remain incompletely elucidated. We conducted exploratory qualitative interviews with 20 HIV-positive YBMSM aged 17-24 and found that father-son relationships were perceived to be important sociocontextual influences in participants' lives. Participants discussed the degree of their fathers' involvement in their lives, emotional qualities of the father-son relationship, communication about sex, and masculine socialization. Participants also described pathways linking father-son relationships to HIV risk, which were mediated by psychological and situational risk scenarios. Our thematic analysis suggests that father-son relationships are important to the psychosocial development of YBMSM, with the potential to either exacerbate or attenuate sexual risk for HIV. Interventions designed to strengthen father-son relationships may provide a promising direction for future health promotion efforts in this population.