Liver fat contents measured by magnetic resonance spectroscopy and chemical-shift water-fat separation imaging were compared in a group of obese adolescents. Distribution of fat in left and right liver lobes was also compared. Results demonstrated that fat contents obtained from both MR modalities were highly correlated and agreed to each other. In obese adolescents with non-alcoholic fatty liver disease, fat distribution was non-uniform between left and right lobes. This study supports the use of fat-fraction map to measure liver fat, which can shorten the scanning time by acquiring information about body adipose tissue and liver fat within a single sequence.