We have experienced the anesthetic management of laparoscopic ovarian cystectomy in a 2-year-old child. The patient was anesthetized with isoflurane and manually ventilated to keep PaCO2 at 30 mmHg prior to the carbon dioxide insufflation of the peritoneal cavity. Two minutes after the abdomen was distended, end-tidal CO2 began to increase and after 10 minutes PaCO2 was 50 mmHg. We had to increase tidal volume and respiratory rate, although airway pressure was 30 cmH2O. We should be careful because children who undergo pneumoperitoneum become hypercapnic easily during general anesthesia.