Retrospective analysis of cholescintigraphy and ultrasonography was done in 76 patients with clinically suspected acute cholecystitis to assess the relative value of the two modalities. Excluding the patients with obstructive jaundice, the overall results of cholescintigraphy(sensitivity 100%, spectificity 95%, false positive rate 5%, false negative rate 0%, accuracy 97%) are nearly identical with or rather superior to those of the ultrasonography(sensitivity 94%, specificity 100%, false positive rate 0%, false negative rate 5%, accuracy 97%). We recommend the cholescintigraphy as the initial modality in patients with clincally suspected acute cholecystitis, and ultrasonography can be used in jaundiced patients to exclude the possibility of the false positive of cholescintigraphy.