Background: Homeless youth are at high risk for HIV infection as a consequence of risky sexual behaviour. Interventions for homeless youth are challenging. Assessment of the effectiveness of interventions to modify sexual risk behaviours for preventing HIV in homeless youth is needed.

Objective: To evaluate and summarize the effectiveness of interventions for modifying sexual risk behaviours and preventing transmission of HIV among homeless youth.

Conclusion: The body of evidence does not permit conclusions on the impact of interventions to modify sexual risk behaviour in homeless youth; more research is required. While the psychosocial and contextual factors that fuel sexual risk behaviours among homeless youth challenge stringent methodologies of RCT's, novel ways for program delivery and trial retention are in need of development. Future trials should comply with rigorous methodology in design, delivery, outcome measurement and reporting.