Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease and is a major public health problem worldwide. It is a spectrum that includes simple steatosis, nonalcoholic steatohepatitis (NASH), fibrosis and cirrhosis. Recently, NAFLD prevalence in children and adolescents has increased too. The increasing prevalence has resulted in NASH-related chronic liver disease. Therefore, early diagnosis and treatment is quite important. Although liver biopsy is still the gold standard for diagnosis and staging of NAFLD, particularly for the diagnosis of NASH, imaging methods such as ultrasonography, computed tomography, magnetic resonance imaging with chemical shift imaging and especially magnetic resonance spectroscopy and elastography have been increasingly approved as noninvasive alternative methods. The aim of this review is to analyze the diagnostic accuracy and limitations of the imaging methods and recent developments in the diagnosis of NAFLD.