The objective of this review study was to analyze the relationship between skeletal muscle mass and postoperative short-term outcomes morbidity in patients with Klatskin tumor who underwent surgical treatment. Low index skeletal muscle mass had a negative impact factor on postoperative morbidity following resection of Klatskin tumor and should therefore be considered as preoperative risk assessment. The further study of body composition in oncological patients allowed revealing the group of patients with high probability of postoperative complications and this factor needed to be added to future models predictive scale of short-term outcomes with the aim of making the most rational preoperative treatment algorithm.