We present two patients with Epstein-Barr virus (EBV) infection related to gallbladder involvement. Such an association is already known as EBV induced acalculous cholecystitis, diagnosed on the basis of ultrasonographic findings. In our patients, radioisotopic cholescintigraphy was also performed and it showed that gallbladder was visualized in both patients in contrast to that what can be observed in cases of cholecystitis. However, the value of ejection fraction was compatible with biliary dyskinesia. We, therefore, consider that impaired gallbladder contractility in EBV infection cases may actually represent biliary dyskinesia and not acalculous cholecystitis taking into account the radioisotopic findings and the self limited course of the disorder.