Risky sexual behaviour such as exposure to pornographic materials, masturbation, prostitution, homosexuality and unprotected sexual intercourse are on the increase. The consequences of these risky sexual behaviours are manifested by rise in unintended teenage pregnancies that result in unsafe abortions and school dropout, HIV/AIDS and other sexually transmitted infections (STIs). The purpose of this study was to investigate selected factors that contribute to risky sexual behaviours among secondary school students. The factors selected for the study were curiosity, peer pressure, economic status and media influence. The study adopted a descriptive survey research design with a target population of 2079 Form 3 and 4 students in all the 16 secondary schools in Molo Central Division. A stratified random sample of 324 Form 3 and 4 students was selected. There were significant gender differences in selected factors contributing to risky sexual behaviour with boys scores being significantly higher than those of girls (p<0.05). This means that boys were more likely to engage in risky sexual behaviour than girls requiring more exposure to guidance and counselling services.