Empirical evidence suggests that a key prerequisite for a supervised injection facility (SIF) utilization is the existence of an “open drug scene,” where users publicly inject drugs. This study seeks to determine the extent and profile of public injecting among injecting drug users (IDUs) in Montreal, Canada, where pilot SIFs are under consideration. A cross-sectional study of IDUs who injected publicly at least once in the previous month was appended to an HIV-risk surveillance study among Montreal IDUs (SurvUDI study). Of 650 SurvUDI participants interviewed between June 2001 and February 2002, 59% were eligible. A dose-response relationship emerged between intensity of public injecting and several drug-use and risk-related characteristics. Regardless of housing stability, IDUs persistently and, often preferably, publicly injected due to habit, dependence, or need to conceal their status. Despite lacking a classical open drug scene, public injecting is common among Montreal IDUs, warranting the consideration of an SIF for this population.