The purpose of this study is to evaluate the changes of liver and gallbladder in patients with acute hepatitis A during transabdominal ultrasonography (US). In this study, we included 61 patients with acute hepatitis A and 50 controls. Wall thickness and lumen diameter of gallbladder were measured for determined the mural edema and hypertonicity of gallbladder. To evaluate the hepatic size and stiffness, two sagittal images of the left lobe of the liver were obtained during the resting state (resting image) and at full inspiration (stress image). The elongation rate was calculated by a formula: (L2-L1/L1)×100 (%); where L1 and L2 are the length of the liver for both the resting and stress image. The elongation rate was compared between controls and patients with acute hepatitis A. The wall thickness and lumen diameter of gallbladder were 7.0±3.5mm, 10.2±9.9mm, respectively. In 21 cases (34%), the lumen of gallbladder was collapsed. The mean diameter of left lobe in patients with acute hepatitis A (10.3±1.4cm)was larger than that of controls (8.2±1.1cm). The elongation rate in patients with acute hepatitis A (8.0±8.8%) was smaller than that of controls (25.5±13.4%). Robust US findings in patients with acute hepatitis A were edematous gallbladder with collapse and hepatomegaly with stiffness.