The main aim of this study is to evaluate the efficacy of total parental nutrition support in comparison with partial parentral nutrition in adult patients undergoing bone marrow transplantation that due to underlying disease, specific drug effects( conditioning regimens) , and nutritional inadequacy as consequence of gastrointestinal dysfunction such as mucositis, vomiting , anorexia , and diarrhea, as well as possible HSCT complications such as infections and graft versus host disease (GVHD) increase the rate of malnutrition during hospital stay. Sixty adult patients are randomized to receive parentral nutrition (total parental nutrition) (n = 30) or control (partial parentral nutrition) (n = 30)after bone marrow transplant. Demographic data, primary admission diagnosis, concomitant disease(s) and co-administered medication(s) are recorded. Subjective global assessment (SGA), nutritional risk screening (NRI), anthropometric measurements, nitrogen balance, and laboratory data (such as albumin, prealbumin and total protein) serum electrolytes (sodium, potassium, magnesium, phosphate) at baseline (24 h after admission) and weekly thereafter during nutrition therapy , are measured and fallow up 100 days after transplant.