OBJECTIVE: To determine the risk factors for severe abruptio placenta in Mulago hospital, Kampala, Uganda. DESIGN: A case control study. SETTING: Mulago hospital labour wards Study population: Women who delivered in Mulago hospital. PARTICIPANTS: Forty five women with severe abruptio placenta (cases) were recruited between 15(th) November 2001 and 30(th) November 2002. They were followed up and compared to five hundred women (controls) who had normal deliveries. OUTCOME VARIABLES: Socio-demographic characteristics, familial history, medical history, gynaecological and obstetric history. RESULTS: The risk factors for severe abruptio placenta were low socio economic status (OR 10.5,95% CI 3.8 to 29.2), co existing hypertension (OR 56.8, 95% CI 9.0 to 358.5), previous history of stillbirth (OR 3.1,95% CI 1.1 to 9.1), delivery by caesarean section in previous pregnancy (OR 7.3, 95% CI 1.8 to 29.7), non attendance of antenatal care(OR 6.5, 95% CI 2.0 to 21.2), recurrent vaginal bleeding(OR 26.7, 95% CI 8.6 to 85.4) and delivery of male babies(OR 2.2, 95% CI: 1.2 to 4.9). CONCLUSION: The risk factors for abruptio placenta were chronic hypertension, recurrent vaginal bleeding, previous delivery with caesarean section and low socio economic status. These factors can be identified during prenatal period and used to prevent maternal morbidity and mortality.