Despite advances in organ procurement and surgical techniques, immunosuppressant therapy continues to present a challenge to graft survival in renal transplantation. It also challenges nurses to give the best care possible. In order to do this, nurses must understand how the immune system functions. They must be able to apply this knowledge to the actions of the immunosuppressant agents their parents are receiving. Immunosuppressant therapy is two-fold. First, it is used to prevent rejection and maintain the function of the graft. Its second use is to reverse acute rejection. The major drugs used in maintenance therapy are the corticosteroids, azathioprine, and cyclosporine. The drugs used in acute rejection are antilymphocyte sera, high-dose corticosteroids, and OKT3. These drugs place the patient at risk for a myriad of serious side effects. By being aware of these side effects, the nurse is able to detect their early signs and symptoms and intervene appropriately.