A to make decisions by themselves. Incidentally such decisions, if not properly guided could either make or mar a person for life. Adolescents have been found to engage in risky sexual behaviours. These behaviours have led to consequences such as sexually transmitted infections, HIV and AIDS, unintended pregnancies, abortions and in some cases death. Studies have shown that being health information literate can aid positive behavioural change. The study therefore, examined the level of health information literacy on sexual issues, and how it aids positive behaviour among adolescents in senior secondary schools in Ogun Central Senatorial district, Nigeria. Survey Research design was used in the study. A sample size of 400 respondents were randomly selected from a population of 127, 021 senior Secondary School Students in Ogun Central Senatorial District. Multistage sampling technique was used to select the participants for the study. Findings revealed that health information literacy among the respondents had a mean of M=2.91 on a 4 points scale. Health information literacy has a critical role to play in the general wellbeing of individuals. Being health information literate is very critical in enhancing positive behaviour and decision making about sexual issues, adolescents who are able to recognize their health information needs, identify likely information sources, evaluate information sources about sexual issues, will be able to apply information to making good decision about sexual issues. Therefore, health information literacy about sexual issues was high among adolescents in Senior Secondary Schools in Ogun Central Senatorial District, Nigeria.