This article provides a historical perspective on the development of syringe exchange in Canada, the Canadian legal and policy context, evaluation and monitoring strategies, and current challenges facing HIV prevention efforts among injecting drug users. Despite the fact that it is legal to sell, exchange, or provide an IDU with a syringe and there are no laws in Canada requiring a physician's prescription to justify possession of a syringe, policy development and programming have not been adequate to hold HIV at bay in several cities across the country. Although there have been concerted efforts by syringe and needle exchange programs to increase the supply of injecting equipment, HIV prevalence continues to rise, provoking a rethinking of the role of syringe exchange. In a coordinated strategy for HIV prevention among drug users in Canada, needle and syringe exchange is not itself in question; however, ghettoization and needle quota systems may have had an adverse impact on prevention programming. A national action plan has been developed which aims to decentralize both methadone maintenance and syringe and needle exchange programs, increase access to detoxification and treatment modalities, and advocate for changes in the criminal justice system and law enforcement practices.