A 1-year study of 529 Yemeni children under 5 years of age hospitalized for severe pneumonia was undertaken to define their clinical characteristics and to identify risk factors associated with death from pneumonia. There were 354 (66.9%) boys, 270 of the 529 (51%) were under 6 months of age and 457 (86.4%) were aged < or = 12 months. The clinical characteristics of the group were as follows. Boys constituted 70% of the group and under-1-year-olds 86%, weight-for-age was under 60% in 23%, clinical rickets was present in 50% and anaemia in 30% (30.1%). On admission, cyanosis was detected in 56%, heart failure in 21% and isolated hepatomegaly in 14%. Fifty-two children died (CFR 9.8%), of whom 25 (48%) were under 6 months of age and 20 (38.5%) were aged between 6 and 12 months. Only seven children aged over 1 year died from pneumonia. Weight-for-age less than 60%, rickets, haemoglobin < 10 g/dl, cyanosis and heart failure were associated with an increased risk of dying from severe pneumonia.