We examined 171 patients who had undergone anterior cervical fusion to determine the frequency and the causes of postoperative respiratory disturbance (PRD). Postoperative tracheal intubation was necessary in 11 patients (6.4%), but only 4 of them (2.3%) required reintubation due to PRD caused by surgical procedures. PRD has been reported to occur at various frequencies in previous studies, partly due to unsettled criteria of PRD, miscellaneous primary diseases, and heterogeneous surgical procedures. As C 3 was fused in the 4 patients with PRD, requiring reintubation, upper airway obstruction due to serious swelling of the soft tissue surrounding C 3 might be the factor leading to postoperative reintubation. One of the PRD patients who suffered from postoperative unilateral phrenic nerve palsy required controlled ventilation.