To clarify the effects of the presurgical vaccination canine parvovirus vaccine (CPV) on immunological responses to surgery in puppies, we assessed it by measuring the blastogenic responses of lymphocytes and delayed type hypersensitivity (DTH) responses after laparotomy in the non- and vaccinated puppies. The inhalation anesthetic used was isoflurane or halothane. In post-surgery, the blastogenic responses of lymphocytes in the non-vaccinated puppies decreased, especially, those in these puppies with halothane anesthesia (GOF) did significantly, and the duration of this decrease prolonged more than that in the non-vaccinated puppies with isoflurane anesthesia (GOI). However, the responses in the vaccinated puppies with each anesthesia didn't almost decrease below the presurgical levels. In GOI groups, the DTH responses in vaccinated puppies increased significantly over those in non-vaccinated ones, but in GOF groups, there were few differences between the DTH responses in the non- and vaccinated puppies. These results suggest that the CPV vaccination immediately before surgery possibly prevents the postsurgical immunosuppression, and that GOI may depress the immunocompetence less than GOF.