We examined potential correlates of sex without HIV disclosure within a sample of 875 participants from the HIV Cost and Services Utilization Study. Interviews with each participant assessed sexual activities with up to six recent partners, and this study included both respondent and partnership characteristics. Compared with marriage and/or primary same-sex relationships, occasional partnerships and one-time encounters were associated with sex with disclosure, and shorter relationships were more likely to involve sex without disclosure. Knowledge of partner serostatus was also associated with sex without disclosure. Women were less likely to have sex without disclosure than men having sex with men. We found an association between the perceived duty to disclosure to all partners and sex without disclosure, while we found no association in multivariate analyses between outcome expectancies and sex without disclosure.