Use of BMT (bone marrow transplatation) has rapidly grown in the last few years. It extends to a variety of neoplastic illnesses and hematological malignancies. This procedure includes implicit appearance of many and important stressors, both physical and psychological, due to the illness and to chemotherapy treatments, among which the appearance and severe colateral effects during the stay in hospital has a special relevance. The need to consider the influency of predictive variables like, prior experiences, optimistic vs. pesimistic expectancies and the strategies of coping used in the adaptation through the treatment, are a central point in the study of the fluctuations of the different psychological responses and their interrelation with the physiology symtomatology which are present during the different phases of the process of BMT.