A study of mothers' perceptions of childhood acute respiratory infections (ARI) was performed in a rural Gambian population. A total of 25,046 interviews were recorded over a 1-year period with mothers from three villages and four hamlets, and these were analysed together with the results of surveillance of their children for episodes of ARI. Mothers recognized acute lower respiratory infection as a severe disease and recognized fast and difficult breathing as features which discriminated it from upper respiratory infections (sensitivity 73%, specificity 73%). They sought treatment for their children on 51% of occasions when chest pain was reported and on 70% of occasions when 'open chest' was reported. We conclude that even in poorly educated populations in which traditional medical beliefs and practices are widespread, it may be possible to educate mothers to identify lower respiratory infections and to seek early treatment. Community education should play a major role in all national ARI programmes and may be a critical determinant of the success of case management strategies in preventing ARI-related mortality in children.