This study examines violence and victimization affecting people exposed to unsheltered, urban homelessness. Findings are drawn from 50 qualitative interviews and observations made while conducting fieldwork among adult members of a large Midwestern American city’s homeless population. Within the studied street-based population, seemingly minor transgressions were found to precede rapidly escalating confrontations that frequently culminated in physical violence. Study findings connect diminished senses of constancy, predictability, and trust in one’s environment – or ontological security, with exposure to physically uncomfortable, victimization-prone, and thus anxiety-ridden unsheltered living conditions. People subjected to such environments are increasingly distrustful, hypervigilant, and sleep-deprived. Consequently, interpersonal, dispute-related processes are undermined and intensified, potentially priming people for aggression and violence. Future efforts to study and address unsheltered homelessness should consider how chronic exposure to arduous and stressful conditions affect abilities to cope with and navigate interpersonal confrontations and disputes.