Free antiretroviral therapy (ART) has been provided through the public health system in Tanzania since 2004. The success of national ART roll out programme is premised upon collaborative efforts of health systems, communities and policy environment. However, community perceptions of ART and its implications on sexual behaviours and HIV/AIDS prevention remain largely unknown. Drawing on focus group discussions with young people, this paper examines perception about ART and the potential impact of antiretroviral therapy on risk sexual behaviour in rural Tanzania. Participants included a purposively selected sample of males and females aged 14-24 years. Results show that young people were both optimistic and concerned regarding availability of ART. Positive attitudes toward ART were associated with public health significance of therapy in managing opportunistic infections and extending lives of HIV infected persons. However, the positive outcomes of therapy were considered to be short lived, unsustainable and potentially threatening to the sexual health and wellbeing of HIV negative members in the community. ART was considered to empower infected persons to intentionally spread HIV to uninfected individuals in the community through deliberate unprotected sexual activities. The study highlights the significance of reinforcing HIV prevention while underscoring the need to provide appropriate information and increasing access to ART in rural areas of Tanzania. In conclusion, creating a therapy friendly atmosphere through information delivery is crucial in promoting social acceptability of antiretroviral therapy among youths. Efforts to improve access to antiretroviral drugs should re-emphasize prevention counselling to minimize sexual transmission of HIV.