Purpose: The purpose of this study was to evaluate the impact of a clinical pathway on infants admitted to a pediatric tertiary care center with the diagnosis of hypertrophic pyloric stenosis (HPS). Methods: The records of 132 HPS patients were evaluated before and after implementation of a clinical pathway. Infants were excluded for prematurity, admission to nonsurgical services, or multiple diagnoses requiring prolonged hospitalization, resulting in 83 patients for analysis. Group I (prepathway, n = 40) and group 11 (postpathway, n = 43) infants were analyzed for time from admission to operation, operation to first feeding, operation to discharge, total length of stay, hospital charges, metabolic status at time of admission, and postoperative complications. The Mann-Whitney test was performed (statistical significance at P < .05). Results: There was no significant difference between group I and group II patients in the length of preoperative hospitalization or metabolic status at the time of hospital admission. In comparison with group I patients, there was a significant reduction in time to resumption of oral feedings (4.6 +/- 1.9 hours v 7.5 +/- 3.2 hours; P < .001) for group 11 infants and a significantly earlier discharge (26.7 +/- 6.8 hours v 38.0 +/- 11.7 hours; P < .001). This resulted in a shortened length of stay (41.8 +/- 9.7 hours v 57.8 +/- 14.3 hours; P < .001) with an associated decrease in hospital charges ($4,555 +/- $464 v $5,400 +/- $1,017; P < .001). Conclusions: Elimination of practice variability by the use of a clinical pathway for HIPS resulted in significant reduction of hospital stay and related charges. The impact of the pathway occurred in the postoperative period and is a consequence of a rapid and systematic return to oral feedings. Copyright 2002 Elsevier Science (USA). All rights reserved.