A 24-year-old male was admitted to our hospital, complaining of right back pain, in May 1995. Chest X-ray films showed an abnormal mass in the mediastinum. Computed tomography revealed massive effusion in the pleural and pericardial space. A biopsy specimen of the pleural lesion demonstrated lymphoblastic lymphoma of T cell type. After the completion of intensive chemotherapy by our original protocol, he entered into partial remission. Peripheral blood stem cells (PBSC) were harvested using a high-dose cytarabine (Ara-C) followed by granulocyte-colony stimulating factor (G-CSF) mobilization regimen. The total number of collected PBSC was enough to perform two courses of PBSCT. In January 1996, following the conditioning regimen of nimustine hydrochloride, etoposide (VP-16), Ara-C, thiotepa, he received PBSCT. Complete remission was achieved after the 1st PBSCT. In March 1996, he received the 2nd PBSCT following the conditioning regimen of carboplatin, VP-16, ifosfamide. No regimen-related toxity or delayed engrafment was observed. Subsequently, he received irradiation to his neck and mediastinum, the primary site of the disease. As of February 1997, he has no evidence of the disease.