Acute acalculous cholecystitis (AAC) in association with acute Epstein-Barr virus (EBV) infection has rarely been described in childhood. In the literature, there are only four reported pediatric cases of AAC associated with isolated primary EBV infection. We present two cases (one new, one retrospectively reviewed) of children with Gilbert's syndrome (GS) who presented with AAC during the course of primary EBV infection. Antibiotics were not used and AAC subsided gradually as the infection regressed. The co-occurrence of GS might have played a contributory role in the pathogenesis of AAC during acute EBV infection.