Malaria in pregnancy jeopardizes the outcome of pregnancy, affecting both the mother and the foetus. The prevalence of placental malaria in women, who routinely attended ante-natal clinics in Owerri, south-eastern Nigeria, was assessed using three hospitals between March 2004 and August 2005. Placental blood was collected in EDTA bottles from incisions made on cleaned basal plate of the placenta, within an hour of delivery. Blood collected was used to assess ABO blood group, haemoglobin level as well as malaria parasitaemia. Malaria parasitaemia was determined from thick and thin smears stained with Giemsa, while the haemoglobin level was measured using the cyanomethaemoglobin method. A total of 586 pregnant women were involved in this study with written consents. Malaria parasites were observed in 175 (29.9%) of the women on delivery. Of these women, 64 (36.6%) were anaemic. A significant relationship at P<0.05 variation, was observed between the prevalence of malaria parasites in the placenta and gravidity, age and blood group. The rate of occurrence of malaria parasitaemia, in the placenta of women who were on a weekly prophylaxis against malaria is alarming and calls for more serious efforts in the prevention of malaria especially in this vulnerable group.