Anemia during pregnancy is highly prevalent in Senegal. For effective intervention, its causes must be known. We determined the prevalence of anemia and the relative contribution of various risk factors in a cohort of 480 women in Dakar. Hemoglobin (Hb), erythrocyte protoporphyrin (EP), serum ferritin (SF), malaria and helminthes infection, Hb phenotype, and dietary iron intake were assessed. Overall, 39% of women were anemic (Hb<110 g/L), 70% were iron deficient (EP>70µmol/mol heme or SF<15µg/L), and 33% had iron deficiency anemia. Twelve percent were infected with P. falciparum; 13% had intestinal helminthes, most of which resided in suburban Dakar. About 7% had sickle cell trait (Hb AS). Women consumed heme-iron containing foods more frequently than non-heme iron foods; however, they also consumed iron absorption inhibitors at high frequency. Iron deficiency more than tripled the risk of anemia. Malaria parasitemia, helminthes infection and Hb AS also increased the risk of anemia, but not significantly. Our findings indicate that for effective control of anemia during pregnancy in Senegal, iron supplementation is needed in addition to education of women about better food choices. Antimalarial chemoprophylaxis should be made available to all women and populations at risk of helminthes infections should be screened and treated.