Background Young people, especially teenagers, between 12 and 19 years are very vulnerable and very susceptible to different kinds of behaviours, most of which are risky and destructive in nature thereby hazarding their lives. Some of them are their engagement in unprotected sex, illicit drugs taking, smoking, alcoholism etc. risky behaviours make them vulnerable HIV and STI. From previous experience, more young people are getting infected which makes the study imperative.

Methods 5 high schools were selected from Ojo Local Government Area of Lagos State, South- Western Nigeria. Official permissions were sought and obtained from the schools to allow students to participate. 50 samples from each school. Samples for study were randomly selected. Descriptive and inferential statistics were used to analyse the collected data.

Results The findings of the study revealed that a significant number of these young people who have had sex and/or are sexually active were introduced into the act by friends and peers. Their chief motivating factor is desire for peer acceptance. The abstainers are so because family, religious beliefs and personal convictions because of their goals which they felt sexual involvement was a distraction. These were the ones with high self-esteem. They were assertive in their relationships and declared boundary lines.

Conclusion Despite awareness and sensitization going on, we discover that young people still engage in risky behaviours which make them prone to STIs and HIV infections. There is therefore a need for advocacy for life skills building for young people that will enable them to effectively manage relationships. This will be in form of assertiveness and self-esteem building in them.