An attempt was made to use a diabetic dog as a model recipient of pancreas transplantation. The diabetic state was induced by total pancreatectomy, and was shown to be stable by oral and intravenous glucose tolerance tests. In dogs that underwent total pancreatectomy under isoflurane anesthesia (GOI), blastogenesis of peripheral blood lymphocytes had a tendency to be reduced in comparison with no-treated dogs until 2 weeks after surgery. However, from 3 weeks after surgery, their responses became comparable to those of non-treated dogs. These results suggest that stable diabetes mellitus is induced, in dogs, by total pancreatectomy, and that this animal is a useful model of a pancreas transplantation recipient.