Data from population-based cancer registries in Europe (nine countries) were used to monitor the incidence of non-Hodgkin's lymphoma in children aged 0-14 years over the 20 year period 1970-1990. The overall annual change in incidence was small--an increase of 0.76% annually, and there was no change at all in infants under one year of age. This differs markedly from the pattern in adults, where quite large increases have occurred.