The common marmoset has been increasingly used for research in the biomedical field; however, there is little information available regarding effective methods of anesthesia in this species. This study retrospectively analyzed 2 regimens of anesthesia induction: intramuscular injection of ketamine followed by inhalation of 5% sevoflurane, and intramuscular injection of midazolam, butorphanol and ketamine followed by inhalation of 5% sevoflurane. Anesthetic depth did not reach the surgical anesthesia stage in 7 out of 99 animals receiving the former regimen, whereas there were only 2 such animals out of 273 receiving the latter regimen. The latter regimen, when followed by maintenance anesthesia with 3% sevoflurane inhalation, was successfully used in various nociceptive procedures. These results indicate that the injection of a combination of midazolam, butorphanol and ketamine followed by inhalation of a high concentration of sevoflurane is effective for anesthesia induction in marmosets.