[Malnutrisi energi dan protein merupakan suatu masalah umum yang ditemukan pada pasien rawat inap di rumah sakit. Berbagai studi menunjukkan sebanyak 40% pasien bedah sudah mengalami malnutrisi pada saat masuk ke rumah sakit. Studi tersebut menunjukkan terdapat hubungan langsung antara penurunan berat badan pra bedah dengan laju mortalitas pasca bedah. Terapi nutrisi perioperatif yang adekuat telah dilaporkan dapat menurunkan laju morbiditas dan menurunkan masa rawat inap secara bermakna. Serial kasus ini terdiri atas empat kasus terapi nutrisi perioperatif pada pasien malnutrisi dengan kanker periampular yang menjalani pembedahan pankreatikoduodenektomi. Pasien adalah laki-laki, berusia antara 40-60 tahun, dengan kanker periampular (pankreas dan ampula Vateri). Keempat pasien kasus ini mengalami sindrom kaheksia-kanker, yaitu ditemukan penurunan BB sebesar 10-15% dalam ena bulan terakhir, anemia, fatigue, dan hipoalbuminemia. Kebutuhan energi total dihitung dengan menggunakan persamaan Harris-Bennedict dengan menambahkan faktor stres sebesar 1,5. Pemberian kalori dan nutrisi dilakukan secara bertahap dan ditingkatkan sesuai dengan perbaikan keadaan klinis, gastrointestinal, dan toleransi asupan pasien. Pemantauan dan evaluasi pasien dilakukan sesuai dengan perubahan subyektif dan obyektif. Selain itu, konseling dan edukasi mengenai terapi nutrisi diberikan setiap hari pada pasien. Selama perawatan, keempat pasien serial kasus ini menunjukkan perbaikan, baik secara subyektif maupun obyektif. Kebutuhan energi total tercapai selama periode pra bedah dan tujuh hingga sembilan hari pasca bedah. Masa rawat pasien ini adalah 12-20 hari. Perbaikan status nutrisi tidak tercapai pada pasien ini, namun terjadi perbaikan kapasitas fungsional dan proses penyembuhan luka yang adekuat. Terapi nutrisi perioperatif yang diberikan diharapkan mampu meningkatkan atau mempertahankan status nutrisi pasien, prognosis pasca bedah, serta meningkatkan kapasitas fungsional dan kualitas hidup pasien secara keseluruhan.;Energy and protein malnutrition are common issues in hospitalized patient worldwide. Various studies had reported that 40% of surgical patient were already malnutrition when admitted to the hospital. The study reported that there were direct relationships between lost of body weight with mortality rate post surgery. Adequate perioperative nutritional therapy had been reported could decrease the morbidity rate and length of stay significantly. This case series consist of four perioperative nutritional management cases in malnourished patients with periampullary cancer that undergone pancreaticoduodenectomy surgery. Patients were male, age between 40-60 years, with periampullary cancer (pancreas & ampulla of Vatery). This four patients were having cancer-cahexia syndrome, which was characterized by lost of body weight 10-15% in the last six months, anemia, fatigue, and hypoalbuminemia. Total energy requirement were calculated with Harris-Bennedict equation with stress factor equal to 1,5. Energy and nutrition were given gradually and increased according to the improvement of clinical & gastrointestinal condition, and food intake tolerance of the patients. Monitoring and evaluation of the patients were applied according to the changes of subjective and objective parameter. Besides that, counseling and education were also given everyday to all of the patients. During the hospitalization, this four case series patients showed improvement, in both subjective and objective parameter. Total energy requirement was achieved in preoperative periode and seven until nine days postoperative in all of this patients. Length of stay of this patients were 12-20 days. Improvement of nutritional status were not found in this patients, but there were significant improvement of functional capacity and wound healing happened in them. Perioperative nutritional management applied to the patients were expected could increase or maintain the patiens’ nutritional status, improve prognosis post surgery functional capacity, and eventually leads to improvement of overall quality of life of the patients., Energy and protein malnutrition are common issues in hospitalized patient worldwide. Various studies had reported that 40% of surgical patient were already malnutrition when admitted to the hospital. The study reported that there were direct relationships between lost of body weight with mortality rate post surgery. Adequate perioperative nutritional therapy had been reported could decrease the morbidity rate and length of stay significantly. This case series consist of four perioperative nutritional management cases in malnourished patients with periampullary cancer that undergone pancreaticoduodenectomy surgery. Patients were male, age between 40-60 years, with periampullary cancer (pancreas & ampulla of Vatery). This four patients were having cancer-cahexia syndrome, which was characterized by lost of body weight 10-15% in the last six months, anemia, fatigue, and hypoalbuminemia. Total energy requirement were calculated with Harris-Bennedict equation with stress factor equal to 1,5. Energy and nutrition were given gradually and increased according to the improvement of clinical & gastrointestinal condition, and food intake tolerance of the patients. Monitoring and evaluation of the patients were applied according to the changes of subjective and objective parameter. Besides that, counseling and education were also given everyday to all of the patients. During the hospitalization, this four case series patients showed improvement, in both subjective and objective parameter. Total energy requirement was achieved in preoperative periode and seven until nine days postoperative in all of this patients. Length of stay of this patients were 12-20 days. Improvement of nutritional status were not found in this patients, but there were significant improvement of functional capacity and wound healing happened in them. Perioperative nutritional management applied to the patients were expected could increase or maintain the patiens’ nutritional status, improve prognosis post surgery functional capacity, and eventually leads to improvement of overall quality of life of the patients.]