The adequate chemical immobilization is an important tool for wildlife management and conservation. The Andean hairy armadillo Chaetophractus nationi is an endemic and poorly known species of the Andean highlands that is classified as Vulnerable by the IUCN. Six adult male specimens of C. nationi from Huachipa Zoological Park in Lima, Peru were anesthetized three times between February and December 2009. A combination of 15 mg/kg ketamine, 1 mg/kg xylazine, and 0.4 mg/kg midazolam was administered by intramuscular (IM) injection. The protocol was partially antagonized with 0.22±0.05 mg/kg yohimbine IM at 50 min post-induction. Heart rate, oxygen saturation, respiratory rate and rectal temperature were recorded every 10 min after the initial application. The induction time, recovery time, degree of muscle relaxation and the presence of defensive reflexes were evaluated. A short induction time (5±1 min) and a rapid and smooth recovery after administration of the antagonist were observed. Recovery time began at 7±2 min and was completed at 15± 4min, presenting good muscle relaxation, presence of defensive reflexes and absence of salivation. Recorded physiological parameters were not significantly altered during anesthesia. This protocol is considered an effective and safe choice for the immobilization of C. nationi for short procedures.