Background/Aims: Diffuse large B-cell lymphoma (DLBCL) in Koreans is frequently accompanied by extranodal (EN) disease at the time of autologous stem cell transplantation (ASCT). We sought to determine whether high EN involvement affected survival following ASCT in Koreans. Methods: We reviewed 27 patients who had DLBCL with residual disease at ASCT: 13 with residual disease at nodal site(s) only and 14 with nodal and EN disease. Results: Univariate analysis showed that disease status, lactate dehydrogenase (LDH), and performance status at ASCT were predictors of survival following ASCT. The number of EN sites, as categorized by the International Prognostic Index system, had no prognostic significance. When EN involvement at ASCT was classified as negative or positive, the 2-year overall survival for the negative group was 64%, significantly better than the 14% for the positive group (p=0.021), and the event-free survival for the negative group was 62%, significantly better than the 14% for the positive group (p=0.02). Conclusions: Patients who had DLBCL with residual EN involvement at ASCT showed worse outcomes following ASCT compared to those without EN disease.