Introduction Incidence of child sexual abuse is increasing worldwide. There is little data on child sexual abuse in the North Western Province of Sri Lanka.Objectives To describe the demographic and medico-legal findings of victims of sexual abuse aged less than 16 years and to identify factors associated with positive findings on medical-legal examination.Methods This cross-sectional analytical study, analysed 132 victims, referred by authorities to General Hospital,Chilaw, from 2012 to 2014.Results Mean age of the victims was 13.1years. Main types abuse were penetrative (61.4%), intra-crural (39.4%) and anal sex (10.6%). The perpetrator was known in 94%. Places of offence were offender's habitat (55.3%), victim's home (23.5%) and secluded areas (11.4%). A positive history of penetrative sex (OR =15.3; 95% CI 5.6-42), chronic sexual abuse (OR=4.8; 95% CI 2.2-10.5) and time lapse in reporting to authorities (OR=4.4; 95% CI 2.0-9.4) were significantly associated with presence of conclusive medical examinations findings. Children were less likely to be willing partners in intra-familial abuse compared to extra-familial abuse where the child was sometimes a willing partner, (OR=0.2; 95% CI 0.07-0.5). Adverse psychological outcomes were observed in 16.7% (n=22).Conclusion Most children were victims of statutory rape and knew the perpetrator. In extra-familial abuse, child was sometimes a willing partner. A positive history of penetrative sex, number of abusive incidents and time lapse for presentation were important factors associated with conclusive medical findings.