PURPOSE: To determine the relative accuracy of barium enema findings of Hirschsprung's disease (HD) and to calculate a level of probability for three signs combined. MATERIAL AND METHODS: Barium enema findings in 45 patients who had undergone rectal biopsy to prove or exclude the diagnosis of HD were retrospectively analyzed by evaluating the presence of a transition zone, irregular contractions and delayed evacuation of barium. Seventeen were neonates (group 1) and the other 28 were infants and children (group 2). The sensitivity, specificity, and positive and negative predictive values of the findings were compared. RESULTS: In visualization of a transition zone, sensitivity, specificity and positive predictive value were 76.5%, 72.7% and 89.7%, respectively. Sensitivity for irregular contractions and delayed evacuation of barium was 76.5% and 91.7%, respectively, whereas for specificity, the corresponding values were 63.6% and 40%. Sensitivities for radiologic signs were higher in group 1 than in group 2, but, the specificities were lower. If two or three findings were positive, the level of probability was 85 - 100%. If two findings were negative, however, the corresponding value was 30%. CONCLUSION: We conclude that the most reliable HD finding is the presence of a transition zone. Irregular contractions and the delayed evacuation of barium are not specific. Two or three positive findings may suggest a higher probability of HD than any single positive finding alone.