222 acute lower respiratory tract infections (LRI), as defined by the World Health Organisation, were identified during one year's surveillance of a cohort of 500 Gambian children aged 0 to 4 years. Symptoms and signs at presentation were related to radiological evidence of lobar consolidation, indicating severe LRI. In infants, a fever of greater than 38.5 degrees C, refusal to breast-feed, or the presence of vomiting were the best predictors of severe LRI. In children aged 1 to 4 years, a fever of greater than 38.5 degrees C or a respiratory rate greater than 60/min were the most accurate clinical signs for severe LRI. Chest indrawing did not discriminate severe LRI. These community-based findings differ from results of hospital-based studies.