• Pediatric acalculous cholecystitis is a well-described though uncommon affliction. However, during the neonatal period nonlithogenic biliary disease is extremely unusual and only isolated reports of this problem exist. Nine previously reported cases are reviewed, and an additional case of a 6-day-old female neonate with a right-upper-quadrant mass is presented in detail. Inflammatory gallbladder disease in the neonate is often associated with concurrent systemic illness. An abdominal mass is palpable in almost all cases. Diagnosis may be confirmed in these patients by radionuclide scanning and ultrasonography. The treatment is cholecystectomy.