This study examined knowledge; attitude and practices of sexually transmitted infections including HIV/AIDS among adolescents in Ghana. A convenient sampling of 150 students from five schools in two suburbs within the Greater Accra Metropolis was used. Findings of the study show that adolescents in the sample have a wide gap between knowledge; attitude and practice with regards to STIs and HIV/AIDS though they become sexually active at an early age. There is also a lack of behavioural change which is reinforced by perceptions and misconception regarding STIs and HIV/AIDS. In the light of the findings of study; continuous and sustained multi-dimensional and holistic education is highlighted as important ingredient in the campaign against HIV/AIDS