As a subgroup of men who have sex with men (MSM), non-gay-identified (NGI) behaviorally bisexual Latino MSM are associated with heightened probabilities of HIV transmission, yet they have eluded HIV/AIDS interventionists. This exploratory study of Puerto Rican MSM drug users employed multi-session qualitative interviews to examine early life experiences related to gender identity and sexual orientation, and the place of risky drug and sexual behaviors in the process of sexual identity formation. NGI participants experienced sexual debut between ages 13 and 20, and most were recruited to prostitution as young teens by NGI age mates who were also members of drug use networks. Participants emphasized their role as insertive sexual partners and that they maintained relationships with pasivo biological males. It is feasible to recruit NGI MSM through primary male sexual partners and drug use networks. HIV/AIDS prevention based on awareness of developmental histories holds promise for intervening before NGI youth engage in male prostitution or injection drug use.