One hundred and fourteen mountain chicken frogs were anesthetized, to place intracoelomic radiotracers. The animals were placed in a clear plastic bag that was filled with isoflurane 5% and oxygen. Loss of righting reflex occurred at 3.4 ± 2.3 min; loss of gular movements was observed at 7.6 ± 2.7 min. Intubation was carried out using a modified cuffed tube between 2.5 and 3.5 mm, at 7.6 ± 2.2 min from the beginning of the anesthesia. Manual intermittent positive pressure ventilation every 5 to 10 sec was initiated and maintained through the anesthesia. Isoflurane concentration was maintained at 2%. Loss of withdrawal reflex occurred at 10.6 ± 4.8 min, while loss of response to painful stimuli was noted at 11.1 ± 2.9 min. Surgery started at 16.9 ± 9.9 min; the procedure from incision to last suture took 8.2 ± 2.3 min. Total anesthesia time was 21 ± 6.4 min. Intermittent positive pressure ventilation was continued with room air until the animals recovered the righting reflex, which occurred at 40.4 ± 10.1 min.