The aim of this study was to examine individual-level factors associated with homelessness in Tehran. Researchers interviewed 318 homeless adults aged 18–80 years in city shelters. Regression results indicated that self-esteem, family attachment, weak social networks, drug abuse, and childhood criminal victimization were all significantly related to homelessness. There has been no systematic investigation on homelessness in Iran, and thus ours is the first study of its kind. We situate our findings in the empirical literature on homelessness from other nations, and describe the implications of our results for the Iranian homeless.