Transplant recipients receive immunosuppressive drugs to prevent graft rejection and graft loss. Immunosuppressive drugs are dosed according to empiric treatment protocols, which consider the risk of under- or oversuppression, rejection, infection, cancer, and drug side effects. An individualized immunosuppressive protocol based on immune monitoring would be useful for avoiding undesired effects. In retrospective studies, numerous immune parameters were shown to be associated with clinical events. Their suitability for clinical application has to be proven in prospective studies. A multiparametric immune monitoring program, performed frequently and lifelong, might be the appropriate approach to predict dysfunction of the graft before clinical symptoms occur.