OBJECTIVE. The purpose of this study was to determine the effect of gallbladder contraction on the conspicuity of flow in the normal gallbladder wall. SUBJECTS AND METHODS. Ten healthy adult volunteers without clinical evidence of gallbladder disease participated in the study. After patients fasted overnight, the gallbladder was scanned using gray-scale, color Doppler, and power Doppler sonography. The subjects were then given a standard meal consisting of 478 ml of a carbohydrate-rich dietary supplement, and the imaging sequence was repeated 20 and 45 min thereafter. Mural flow was graded using a four-step grading scheme. Gallbladder volume, wall thickness, and visibility of mural flow at all three time points were statistically compared. RESULTS. Enhanced mural flow was seen after meal consumption in all but one volunteer. Overall, mural flow was significantly greater 45 min after eating than at baseline or 20 min on color Doppler sonography (p = .004) and power Doppler sonography (p = .008). CONCLUSION. Flow in the gallbladder wall is a normal finding that is seen more easily when the gallbladder is contracted. This fact must be kept in mind when sonography is used with patients in whom acute cholecystitis is suspected, particularly if they do not fast before sonography.