Children and adolescents, who received an autologous reimplant of the spleen because of traumatic injury between 1979 and 1986 were matched to a cohort of patients, splenectomized because of traumatic injury of the spleen as well and to a control group of healthy age matched individuals. In addition to a physical check-up, markers of humoral and cellular immunity (e.g. lymphocyte subpopulations and phagocytosis of pneumococcy) as well as the coagulatory and fibrinolytic system were examined. All parameters tested, were found to between results from splenectomized and healthy individuals. Our studies stress the fundamental ability of autologous spleen transplants to take over part of the splenic function on the basis of a largerly histomorphologic restitution. Thus autologous reimplantation of the spleen in children and adolescents is an excellent choice as compared to otherwise necessary splenectomy, if preservation of the organ is impossible.