Background The patients with nonalcoholic fatty liver disease demonstrate an increased cardiovascular risk. The adverse influence of liver abnormalities on cardiac function are among many postulated mechanisms behind this association. The aim of the study was to evaluate cardiac morphology and function in patients with morbid obesity referred for bariatric surgery with liver biopsy. Methods and Results We evaluated with echocardiography 171 consecutive patients without known cardiac disease (median age 42 [interquartile range, 37-48] years, median body mass index 43.7 [interquartile range, 41.0-47.5], 67% female patients. Based on the liver biopsy results, there were 44 patients with nonalcoholic steatohepatitis (NASH), 69 patients with isolated steatosis, and 58 patients without steatosis. Patients with NASH demonstrated signs of left ventricular concentric remodeling and hyperdynamic circulation, including indexed left ventricular end-diastolic diameter [cm/m]: NASH 1.87 [0.22]; isolated steatosis 2.03 [0.33]; without steatosis 2.01 [0.19], =0.001; relative wall thickness: NASH 0.49±0.05, isolated steatosis 0.47±0.06, without steatosis 0.46±0.06, =0.011; cardiac index [L/m]: NASH 3.05±0.54, isolated steatosis 2.80±0.44, without steatosis 2.79±0.50, =0.013. After adjustment for sex, age, blood pressure, and heart rate, most of the measures of the left ventricular systolic and diastolic function, left atrial size, right ventricular function, and right ventricular size did not differ between groups. Conclusions In a group of patients with extreme obesity, NASH was associated with left ventricular concentric remodeling and hyperdynamic circulation. Increased cardiac output in NASH may represent an additional risk factor for incident cardiovascular events in this population.