The duration of gastroesophageal reflux disease (GERD) is an important factor in the development of esophageal complications. The objective of this study was to examine in a retrospective, case-controlled manner the prevalence of GERD in adults who were diagnosed with GERD in infancy or early childhood. Infants and children with nonsyndromic GERD diagnosed by an experienced pediatric gastroenterologist from 1976 to 1980 and control subjects seen for well-child care from 1980 to 1985 were included in this study. The subjects were located and contacted by telephone or mail and administered a brief structured questionnaire relating to their current history of GERD. GERD-A was defined as weekly heartburn or regurgitation of any severity, and GERD-B was defined as monthly heartburn or regurgitation greater than mild in severity. Sixty-five participants (31 patients and 34 controls) returned completed questionnaires and were subdivided into the three study groups as follows: Infant (15), Child (16), and Control (34). The prevalence of adulthood GERD-A was 13, 31, and 21% in the Infant, Child, and Control groups, respectively. Similarly, the prevalence of adulthood GERD-B was 20%, 44%, and 24%, respectively. The Child group tended to report more severe heartburn than the other groups. The Infant group tended to report more frequent regurgitation, and the Child group also reported a higher prevalence of nocturnal heartburn and more frequent use of GERD medications, although these were not statistically significant. These data suggest that pediatric GER is a heterogeneous disorder and that GERD occurring after infancy may be more predictive of the presence of GERD during adulthood. Longitudinal follow-up of a larger number of children is needed to answer the question of when classic adulthood GERD begins.