To study factors related to recurrent laryngeal nerve (RLN) paralysis, a major complication of thyroidectomy.Retrospective study of outcome of patient's medical records in Xijing Hospital and Tumor Hospital of Liaoning Province. Records of 1,563 patients who underwent thyroidectomy by departments of general surgery, ENT and head & neck surgery at these two hospitals were reviewed for RLN paralysis.RLN injury was analyzed in relation to types of surgery, RLN identification, and histopathology.The incidence of RLN paralysis was 7.8%, and significantly related to the histopathologic findings of malignancy (P < 0.01). The positive identification and prevention of RLN would not be in either permanent RLN paralysis or temporary RLN paralysis, and the types of surgery were not found to be significant factors in both paralysis.RLNs should be identified to avoid iatrogenic injury and subsequent paralysis, and meticulous surgical technique should be applied in patients whose results of biopsy suggested malignancy.