The purpose of this study was to analyze the peculiar involvement of the gallbladder in childhood metachromatic leukodystrophy. Seven consecutive children (four boys, three girls; age range, 9 to 58 months old; mean age, 24.3 months) with biochemically confirmed metachromatic leukodystrophy were studied with abdominal ultrasonography. Four of them showed abnormal findings, such as diffuse thickening of the gallbladder wall (more than 3 mm thick), sludge-like echogenic material, or papillary polypoid ingrowth of inner wall obliterating the lumen. In childhood metachromatic leukodystrophy, the characteristic abnormality of the gallbladder on ultrasonography may serve as an ancillary diagnostic clue to supplement the clinical and MR imaging findings, facilitating the differential diagnosis from the other, similar leukodystrophies.