Objective: To report on the haemoglobin concentrations and prevalence of anaemia in schoolchildren in eight countries in Africa and Asia. Design: Blood samples were collected during surveys of the health of schoolchildren as a part of programmes to develop school-based health services. Setting: Rural schools in Ghana, Indonesia, Kenya, Malawi, Mali, Mozambique, Tanzania and Vietnam. Subjects: Nearly 14 000 children enrolled in basic education in three age ranges (7-11 years, 12-14 years and >/= 15 years) which reflect the new UNICEF/WHO thresholds to define anaemia. Results: Anaemia was found to be a severe public health problem (defined as >40% anaemic) in five African countries for children aged 7-11 years and in four of the same cou...