Anaemia during pregnancy is an important contributor to maternal mortality and morbidity in Kenya. A prospective study was conducted in Kisumu District, a region characterized by high incidences of maternal and infant mortality, to determine the levels and prevalence of maternal complications. Four health facilities were purposely selected to act as sentinel centres from urban and rural clusters. All the obstetric-related cases were recorded between January and July 1997, and the outcomes of the pregnancies were recorded. Details on the respondents socioeconomic, demographic, biomedical and environment characteristics were also recorded. A total of 1,455 cases were recorded, of which 59 percent experienced obstetric-related complications. Of those with complications, 22 percent were suffering from severe anaemia. Among other things, the study reveals that anaemia prevalence is determined by maternal and environmental factors. These include poor pregnancy care, illness during pregnancy, socioeconomic conditions of the mother and the sanitary conditions of the household. Policy measures aimed at managing anaemia should seek to address all these factors.