This paper examines factors that may predispose unmarried and unemployed out-of-school youth to risky sexual behaviour. Data for analysis were derived from the Behaviour Surveillance Survey carried out in Kenya in late 2002. A total of 6129 male and female unmarried and unemployed out-of-school youth in the age range 15–24 years were successfully interviewed. However, for this paper only a sample of 3961 comprising sexually experienced youth in the 12 months preceding the survey was used. Methods of analysis included descriptive statistics and multinomial logistic regression. Results for males indicate that factors associated with low and high risk were whether they had fathered a child, district of residence and frequency of alcohol use, while current age and age at first sexual debut stood out for those with low risk alone. For females the district of residence and age of partner at sexual debut were the factors that predisposed them to low-risk sexual behaviour, while for high risk the district of residence, current age and ever being pregnant were significant. The results indicate that for these youth, contextual and probably social factors appear to be the main determinants of risky sexual behaviour for both males and females. The findings also support those of other studies that link risky sexual behaviour among youth, especially males, to alcohol consumption. Programmes for intervention therefore need to focus on these aspects. There is also a need for studies that can look at district-specific factors for more focused interventions.