A 40-yr-old female received a living-related renal transplantation on January 29, 2008. She had type I diabetes mellitus and pyoderma gangrenosum (PG). Induction immunosuppressive therapy consisted of tacrolimus, mycophenolate mofetil, basiliximab, and prednisolone. Intravenous methylprednisolone pulse therapy was administered to prevent ulceration at the surgical site. The postoperative outcome was almost uneventful, and renal graft function was well preserved for 11 months. Her graft function deteriorated on December 24, 2008 and thus an episode biopsy was performed. The histopathological findings were consistent with plasma cell-rich acute rejection (PCAR). During hospitalization, it was noted that the patient was non-compliant. We then performed steroid pulse therapy, and her graft function and histological findings improved. This is the first report of PCAR in a patient with PG who received a renal allograft. It was thought that PCAR was triggered because of her non-compliance. Thus, we should recognize the importance of enhancing compliance in transplant recipients.