OBJECTIVE: Preeclampsia is one of the most common complications of pregnancy with the trophoblast implicated in its onset. Since human chorionic gonadotropin (hCG) is secreted by trophoblast, I hypothesized that there is an association between human chorionic gonadotrophin and its onset. The purpose of the study was to determine if there is an ssociation between β hCG and preeclampsia. METHODS: This was a case control study of 50 pregnant women with preeclampsia (case group) and 50 normal pregnant cases (control group) marched for age, parity and gestational age in the Department of Obstetric and Gynaecology, Lagos University Teaching Hospital Idi Araba Lagos. Serum beta-hCG in all cases were measured by radioimmunoassay. The mean βhCG level in preeclampsia (mild and severe) was compared with normal cases using P value set at 0.05.