Patients with peripheral T-cell lymphoma demonstrated a poor prognosis after obtaining a complete response with induction treatment compared to those with B-cell lymphoma. Once it relapsed, curative treatment is frequently limited to invasive treatments with significant treatment-related mortality, including allogeneic stem cell transplantation. The limitations of these treatment choices indicate the necessity for developing optimal consolidation therapies to prevent relapse. This multicenter randomized phase III trial aims to confirm the superiority of the high-dose therapy with autologous stem cell transplantation over observation alone in terms of progression-free survival for patients with newly diagnosed peripheral T-cell lymphoma who achieved complete metabolic response after induction therapy. A total of 140 patients from 52 hospitals will be enrolled in Japan over 5.5 years. This trial is registered in the Japan Registry of Clinical Trials as jRCTs031240169 (https://jrct.niph.go.jp/latest-detail/jRCTs031240169).