PURPOSE: Gallbladder (GB) wall thickening can be found in various conditions unrelated to intrinsic GB disease. We investigated the predisposing etiologies and the outcome of acalculous GB wall thickening in children. METHODS: We retrospectively analyzed 67 children with acalculous GB wall thickening who had visited our institute from June 2010 to June 2013. GB wall thickening was defined as a GB wall diameter >3.5 mm on abdominal ultrasound examination or computed tomography. Underlying diseases associated with GB wall thickening, treatment, and outcomes were studied. RESULTS: There were 36 boys and 31 girls (mean age, 8.5+/-4.8 years [range, 7 months-16 years]). Systemic infection in 24 patients (35.8%), acute hepatitis in 18 (26.9%), systemic disease in 11 (16.4%), hemophagocytic lymphohistiocytosis in 4 (6.0%), acute pancreatitis in 3 (4.5%), and specific liver disease in 3 (4.5%) predisposed patients to GB wall thickening. Systemic infections were caused by bacteria in 10 patients (41.7%), viruses in 5 patients (20.8%), and fungi in 2 patients (8.3%). Systemic diseases observed were systemic lupus erythematosus in 2, drug-induced hypersensitivity in 2, congestive heart failure in 2, renal disorder in 2. Sixty-one patients (91.0%) received symptomatic treatments or treatment for underlying diseases. Five patients (7.5%) died from underlying diseases. Cholecystectomy was performed in 3 patients during treatment of the underlying disease. CONCLUSION: A wide range of extracholecystic conditions cause diffuse GB wall thickening that resolves spontaneously or with treatment of underlying diseases. Surgical treatments should be avoided if there are no definite clinical manifestations of cholecystitis.