To compare the postoperative outcome according to the type of anesthesia, formerly prematured and high-risk infants who had received and weaned ventilator care preoperatively and had undergone inguinal herniorrhaphy were enrolled in this study. Immediate pre- and post-operative respiratory data which contained the lowest respiratory rates, SpO₂, heart rates and the incidence of hypoxemia and bradycardia were collected with the incidence of ventilator care, application of continuous positive airway pressure (CPAP), application of oxygen, hospital stay, and respiratory mortality by chart review, retrospectively. Among the twenty-nine infants, fourteen received the general anesthesia (GA group), and fifteen received the spinal anesthesia (SA group). Postoperatively, the infants in the GA group had lower SpO₂ (77.1 ± 20.9% vs. 93.0 ± 5.5%), higher incidence of hypoxemia (6 vs. 0), ventilator care (5 vs. 0) and application of CPAP (4 vs. 0) than the infants in the SA group. One infant in the GA group died because of acute respiratory failure caused by respiratory syncythial virus pneumonia. We concluded that spinal anesthesia reduces postoperative oxygen desaturation and respiratory morbidity in formerly prematured and high-risk infants who underwent inguinal herniorrhaphy.