Adolescence is the time of life in which the most important transformations take place. There is also an evolutionary “ break down”, a period in which the somatic and the psychic evolution run along very different paths and at different speeds. Both contracting a potentially lethal disease and facing such hard treatment as bone marrow transplantation create strong interference of the growth process. In our Bone Marrow Transplantation-Unit over the past year we began observing 7 patients who were between 12 and 17 years of age, starting from when diagnosis was communicated and for the whole time they were under treatment. Simultaneously we studied 7 adolescents who had undergone transplantation and were off treatment for at least two years. We preferred to carry out psychodynamic interviews rather than psychometric tests because we realized that the latter were not well accepted by the adolescents. The data obtained from the observation and interviews reveal that the most disturbing facts regard the “ fragmentation of the ego”, fantasies about death and resurrection and above all about their sexual identities when the donor is of opposite gender. We saw two adolescents who developed psychotic access. In one case this took place during hospitalisation and in the other at release. Some very meaningful data regard the high frequency of “ panic attacks”. In our country this disturbance is at present more frequent than it ever was in the past, yet however is lower than in adolescents who have undergone transplantation.