The authors review 1,636 cases of total thyroidectomy with reference to specific complications, classifying them under the headings: major-minor, early-late, transitory-definitive. They report 19 cases of postsurgical haemorrhage, all within 12 hours of the operation, 31 transitory and 15 definitive cases of recurrent laryngeal nerve paralysis, and 14 cases of definitive hypoparathyroidism. As far as the minor complications were concerned, there was a greater incidence of seroma following the use of the harmonic scalpel. The risk factors and physiopathological mechanisms associated with each type of complication are analysed here, above all those responsible for the major and definitive complications. The need for routine preparation of the recurrent nerve, in order to prevent occurrence of postsurgical paralysis is stressed, as is the efficacy of vitamin D in preventing symptomatic postsurgical hypocalcaemia.