Post-Transplant Lymphoproliferative disease remains a serious morbidity. We report a case of complete regression of a biopsy proven B-Cell lymphoma that occurred in the post transplant period. A 48 years old gentleman received a living renal transplant for end stage renal disease due to undetermined etiology. His initial immunosuppresion consisted of corticotheray, mycophenolate and ciclosporin. The patient developed severe pneumonia within the first two months of the transplantation due to Acinobacter, Pneumocystosis and probably CMV infection. He had a complete recovery from this pneumonia and was discharged for follow up at his regional hospital. 4 months after discharge the patient was referred again because of presence of two nodules on his trunk. The biopsy of the nodules revealed B-Cell lymphoma. Ciclosporin was stopped and sirolimus was started. The lesions regressed progressively to be complete within 6 months. The patient remains well without clinical relapses 19 months after conversion. Renal functions remained stable. We postulate that the antineoplastic properties of sirolimus may have played an active part in the positive outcome.