A study was undertaken in the Farafenni area of The Gambia to determine the relation between morbidity from malaria in children and the use of bed-nets (mosquito-nets). From comparisons of parasite and spleen rates in bed-net users and in non-users it seemed that bed-nets had a strong protective effect. However, the prevalence of malaria in the study population was also influenced by ethnic group and place of residence, and the association of bed-net use with these two confounding factors accounted for some of the differences observed between bed-net users and non-users. Nevertheless, a significant inverse correlation between splenomegaly and the use of bed-nets remained. This suggests that bed-nets give Gambian children some protection against malaria and that the use of bed-nets, either untreated or treated with an insecticide such as permethrin, should be investigated further as a means of malaria control in Africa.