This paper presents experience with cyclosporine A in kidney allograft recipients at the Transplantation Institute, the Medical University of Warsaw. Comparative studies on pharmacokinetics and bioavailability of CsA and Neoral as well as monitoring of the drug immunosuppressive activity are presented. The implementation of CsA to immunosuppressive therapy in renal allograft recipients have greatly improved the grafts and patients survival. CsA has been used in a great percentage of patients after renal allograft in Poland (72%) and seems to be in some patients the gold standard of immunosuppression.