Erythrocyte protoporphyrin (EPP) concentration was determined in 87 children who presented at the Adeoyo General Hospital and the University Teaching Hospital (Ibadan, Nigeria) for various ailments. Presence or absence of anaemia was based on haemoglobin concentration. There was a significant difference (p < 0.01) between the mean haemoglobin values of the severely anaemic, mildly anaemic and control children. There was no significant difference (p > 0.05) between the mean haematocrit, mean EPP and mean EPP:Hb ratio of the mildly anaemic and control groups, but corresponding values for the severely anaemic group differed significantly (p < 0.001) from the values for the others. The increase in EPP was correlated with the decrease in Hb concentration(r = -0.8263, p < 0.001), suggesting that iron deficiency was a major cause of severe anaemia. EPP alone or in combination with Hb is effective in identifying anaemic individuals, while Hb alone tends to over-estimate the occurrence of iron deficiency anaemia. EPP values above 100 µg/100 ml of erythrocytes identified severe anaemia.