In terms of nutritional therapy after pancreatectomy, there is no need for routine use of artificial nutrition supplementation except in the case of malnutrition or complications. Postoperative pancreatic fistula (POPF) is one of the most representative complications of pancreatectomy, and adequate nutritional support is important for management of POPF. Oral diet or enteral nutrition (EN) treatment is preferred over parenteral nutrition (PN) since oral diet or EN results in higher POPF closure rates and lower complication rates than EN. Postoperative pancreatitis is usually managed according to the general principle of acute pancreatitis. There is no need to provide specialized nutrition therapy for mild pancreatitis, whereas moderate-to severe pancreatitis should be treated with early specialized nutritional therapy. EN is a more preferred nutritional supplement method over PN due to its lower complication rate, shorter hospital stay, less frequent multi-organ failure, and mortality. Long-term sequelae after POPF or pancreatitis include exocrine or endocrine insufficiency. In the case of exocrine insufficiency, exocrine replacement therapy should be administered. Moreover, endocrine insufficiency, commonly represented by diabetes mellitus (DM), should be managed based on guidelines for type 1 or 2 DM.