Child rape violates human rights and causes immediate and long-term health problems for the child. In the 1998 South Africa Demographic and Health Survey, we assessed frequency of rape in a nationally representative study of 11735 women aged 15-49 years. 153 (1.6%, 95% CI 1.2-1.9%) of these women had been raped (forced or persuaded to have sex against their will) before the age of 15 years. Our results show that younger women were significantly more likely to report rape than older women (p<0.0001). The largest group of perpetrators (33%) were school teachers. Our findings suggest that child rape is becoming more common, and lend support to qualitative research of sexual harassment of female students in schools in Africa.