This review examines the relations between early childhood lower respiratory symptoms and adult respiratory disease. The problems associated with investigating potential associations between respiratory disease in children and adults are discussed. Some studies have limitations because they are retrospective and early childhood respiratory symptoms have not been accurately diagnosed. Therefore, in this review, particular attention is paid to longitudinal studies (some from birth) that have used strict diagnostic criteria for respiratory episodes. These studies provide unique insights into the risk factors for the development of childhood respiratory problems and for persistence of symptoms into adulthood. Although cross-sectional studies have indicated that early childhood respiratory disease is more frequent in adults with respiratory disease, evidence from longitudinal studies suggests that respiratory symptoms such as wheezing, are transient in the majority of infants and result from developmentally small airways. These longitudinal investigations have also indicated that persistence of symptoms into later childhood is associated with atopy. The important role of cigarette-smoke exposure as a risk factor for abnormal pulmonary development, persistence of respiratory disease and reduction in lung function is discussed. The discovery of genetic markers associated with respiratory syndromes such as asthma, should facilitate studies that investigate the childhood antecedents of adult respiratory disease. Future longitudinal studies using genetic markers, will allow relations between specific genotypes and phenotypic outcomes to be examined.