Diagnosing Hirschsprung's disease is a clinical challenge. Hirschsprung's disease should be considered in any child who has a history of constipation dating back to the newborn period. We examined diagnostic methods and their results retrospectively in 37 neonates and infants who underwent both barium enema and anorectal manometry for the diagnosis of Hirschsprungs disease at Asan Medical Center between January 1999 and April 2001. Two radiologists and a surgeon repeatedly reviewed both of the diagnostic results. In anorectal manometry, thirty-four studies were in agreement with the definitive diagnosis, giving an overall diagnostic accuracy of 91.9 % (neonate; 100 %, infant; 85.7 %). The accuracy and specificity of barium enema was lower than those of anorectal manometry, but sensitivity was higher. There was no significant difference between the two methods. Both studies showed findings consistent with the final diagnosis. However, discordant results needed further evaluation or close observation to diagnose accurately. We conclude that Hirschsprungs disease should not be diagnosed by only one diagnostic method.