Background The prevalence of anaemia in Africa is the highest in the world. Especially women are at risk because of blood loss during menstruation and increased iron requirements during pregnancy. This study examined determinants of the haemoglobin (Hb) level of African women at individual/household, cluster, district, and national level. Special attention was paid to socioeconomic factors and the presence of health facilities.

Methods Data were derived from Demographic and Health Surveys conducted between 2003 and 2010 in 21 African countries. We included all women aged 15–49 who participated in a women's survey and had a Hb measurement. Multilevel models were used to examine the influence of various factors at different hierarchical levels simultaneously.

Results 104 899 women were included in the study, of which 23.1% were anaemic (Hb<110 g/L). Socioeconomic factors were strongly related to the Hb level of women. Wealth, education, having a job, occupation of the partner, presence of a toilet facility, context educational level and preventive health measures were positively associated with the Hb level. Interaction analysis indicated that socioeconomic differences in the Hb level of women were reduced by the presence of health facilities.

Conclusions Interventions aimed at improving the Hb level of African women should take socioeconomic and contextual aspects into account. Increasing availability of health facilities might be a tool for reducing socioeconomic differences.