A school health education programme in primary schools aimed at AIDS prevention in Soroti district of Uganda emphasized improved access to information, improved peer interaction and improved quality of performance of the existing school health education system. A cross-sectional sample of students, average age 14 years, in their final year of primary school was surveyed before and after 2 years of interventions. The percentage of students who stated they had been sexually active fell from 42.9% (123 of 287) to 11.1% (31 of 280) in the intervention group, while no significant change was recorded in a control group. The changes remained significant when segregated by gender or rural and urban location. Students in the intervention group tended to speak to peers and teachers more often about sexual matters. Increases in reasons given by students for abstaining from sex over the study period occurred in those reasons associated with a rational decisionmaking model rather than a punishment model. A primary school health education programme which emphasizes social interaction methods can be effective in increasing sexual abstinence among school-going adolescents in Uganda. The programme does not have to be expensive and can be implemented with staff present in most districts in the region.