Nutritional screening and assessment should be a standard of care for all patients because nutritional management plays an important role in clinical practice. However, there is no gold standard for the diagnosis of malnutrition or undernutrition, although a large number of nutritional screening and assessment tools have been developed. Nutritional screening and assessment tools are classified into two categories, namely, subjective global assessment (SGA) and objective data assessment (ODA). SGA assesses nutritional status based on the features of medical history and physical examination. On the other hand, ODA consists of objective data provided from various analyses, such as anthropometry, bioimpedance analysis (BIA), dual-energy X-ray absorptiometry (DEXA), computed tomography (CT), magnetic resonance imaging (MRI), laboratory tests, and functional tests. This review highlights knowledge on the performance of ODA methods for the assessment of nutritional status in clinical practice. J. Med. Invest. 62: 119-122, August, 2015.