Evidence links unstable housing, and especially homelessness, with elevated health harm among drug users, including riskier drug injecting practices. We undertook 45 qualitative interviews with injecting drug users (IDUs) in Bristol and London in 2006, the majority of whom had recently experienced homelessness. IDUs were recruited through drug user networks and drug agencies. We undertook thematic analyses of drug injector accounts concentrating on risk linked to drug injecting in a context of unstable housing. Findings show that temporary accommodation and hostels for the homeless may provide a 'safe haven' from street-based drug use and public injecting environments, and are characterized as a retreat from the 'chaos' of the street. But hostels may also constitute 'risk environments', facilitating drug using and risk networks and transitions to new patterns of use, including increased frequency of injecting. For some, homelessness was positioned as 'safer' than temporary housing with regards to managing drug use. Stable housing emerges as a key structural factor in creating enabling environments for health. We emphasize that temporary accommodation hostels have potential for harm-reduction interventions, but may also be associated with the production of risk related to drug use and injecting. © 2009 Informa UK Ltd All rights reserved.