Objective:To investigate the optimal time of tracheotomy/arytenoidectomy and the improvement of dyspnoea, dysphonia and dysphagia after arytenoidectomy with CO₂ laser in iatrogenic bilateral vocal folds paralysis patients. Method:Thirty patients [29 females, 56 (49-60) years, one male, 49 years] with bilateral vocal cords paralysis resulted from neck surgery were retrospectively analyzed by case archived information and following-up questionnaire. The data included patients' dysponea time, degree and duration from tracheotomy/arytenoidectomy to neck surgery. Twenty sixty patients required unilateral partial/total arytenoidectomy. The results of treatment were evaluated by questionnaire including dyspnoea, dysphonia and dysphagia. Result:All patients whose bilateral vocal paralysis were resulted from thyroid gland surgery. Dysponea occurred immediately after thyroidectomy surgery in 14 cases (46.7%), and 2 years later after thyroidectomy in 13 cases (43.3%), 8 years later in 3 cases (10.0%). There was one (3.3%) patient without tracheotomy. The duration of tracheotomy/arytenoidectomy to neck surgery was significantly correlated with duration of tracheotomy/arytenoidectomy to dyspnoea appearance (r=0.879, P<0.05), not correlated with duration of thyroid surgery to dyspnoea appearance. There is significantly negative correlation between degree of dyspnoea and duration of tracheotomy/arytenoidectomy to neck surgery (r=0.452, P<0.05). Twenty six patients appeared dyspnoea and underwent CO₂ laser arytenoidectomy after thyoidectomy 0.5-23 years. Five patients did unilateral total arytenoidectomy and 21 patients did unilateral partial arytenoidectomy. After 12-96 months following up, dyspnoea improved in 24 patients, no improved in 2 patients. Dysphonia improved and remained in 17 patients, being worse mildly in 8 patients and obviously in one patient. Dysphagia improved and remained in 24 patients, being worse in 2 patients. There was no difference between total and partial arytenoidectomy in dyspnoea, dysphonia and dysphagia. Conclusion:The morbidity of dyspnoea was correlated with time after neck surgery. It was rarely necessary to take tracheotomy immediately in bilateral vocal fords paralysis patients after neck surgery. The severer degree of dyspnoea led to shorter duration between neck surgery and tracheotomy/arytenoidectomy. There was obvious improvement after arytenoidectomy in dyspnoea, no significant change in dysphonia and dysphagia. The effect of total arytenoidectomy on bilateral vocal paralysis was similar to partial arytenoidectomy.