Background: Research on homeless youth has shown that this population is at high risk for various mental health problems. Previous studies conducted among homeless young adults in Ghana have focused primarily on economic, social and cultural causes of homelessness, their engagement in risky sexual behaviours and the prevalence of STI including HIV/AIDS. We are therefore not fully informed of the prevalence of psychological symptoms and their associated factors. The aim of the study was to determine the association between psychological functioning and social and health risk behaviours among a sample of homeless youth in Ghana. Methods: A cross-sectional survey of a convenience sample of 227 (122 male and 105 female) homeless youth was conducted in Ghana in 2013. An interviewer-administered questionnaire was used to collect data due to low level of literacy among the study population. Pearson-moment correlation coefficient (r) and multiple standard regression models were fitted to analyse the data. Results: Approximately 87% of the participants in this study exhibited moderate to severe psychosocial symptoms. Specifically, emotional, conduct, hyperactivity and peer relationship problems among the participants were 69%, 74%, 54% and 89% respectively. Overall psychosocial functioning was predicted by stigma (self-stigma and experienced stigma), violent behaviours and suicidal ideation. Substance use and perceived resilience were significantly associated with emotional problems. Conclusion: There is a need for holistic interventions to help improve the psychological and social functioning of homeless youth. Such programmes should strengthen socio-emotional coping strategies in street youth as well as address contextual risk factors such as stigma and discrimination by the public.