Epidemiological and clinical aspects of 233 children below 14 years of age with acute carbon-monoxide poisoning are presented. Patients were recorded in the retrospective part of the M.S.P.C. (Multicentre Study of Poisoning in Children) at Genova, Torino and Trieste pediatric hospitals during 1975/90. Carbon-monoxide poisoning resulted to be a main toxic risk in children by considering its frequency and the severity of symptoms; three cases of death occurred. In particular, differences between symptoms in small children (under the age of 4 years) and adults are emphasised. This poisoning has to be suspected even in the presence of minor symptoms; the blood carboxyhemoglobin assay confirms the diagnosis and is useful to avoid further exposure.