The current study presents a case of primary T-cell lymphoma (PTBL), unspecified, in a 27-year-old female. The patient received chemotherapy [cyclophosphamide, epirubicin, vindesine and prednisolone (CHOP) and VP-16 plus CHOP (ECHOP)] and autologous peripheral blood stem cell transplantation, however, relapse occurred rapidly. The recurrent tumor exhibited increased levels of karyopyknosis and nuclear fragmentation and a higher Ki67 index compared with the primary tumor. No response to subsequent chemotherapy, including ECHOP and gemcitabine, dexamethasone and cisplatin, was observed. The patient succumbed to PTBL, unspecified, 18 months after the diagnosis. We hypothesize that autologous peripheral blood stem cell transplantation is ineffective for PTBL.