We sought to identify the prevalence and independent correlates of condomless sex within a cohort of community-recruited homeless and unstably housed cisgender adult women who were followed biannually for 3 years (N = 143 HIV+ , N = 139 HIV-). Nearly half (44%) of participants reported condomless sex in the 6 months before baseline, which increased to 65% throughout the study period. After adjusting for having a primary partner, longitudinal odds of condomless sex among women with HIV were significantly higher among those reporting < daily use of alcohol or cannabis (AOR = 2.09, p =.002, and 1.88, p =.005, respectively) and PTSD (AOR = 1.66, p =.034). Among women without HIV, adjusted longitudinal odds of condomless sex were significantly higher for those reporting < daily methamphetamine use (AOR = 2.02, p =.012), panic attack (AOR = 1.74, p =.029), and homelessness (AOR = 1.67, p = .006). Associations were slightly attenuated when adjusting for sex exchange. Targeted HIV/STI programs for unstably housed women should address anxiety and trauma disorders, infrequent substance use, and housing challenges.