This is a multicentric open phase IV randomized controlled trial comparing patients submitted to total thyroidectomy comparing standard surgical procedure versus Harmonic scalpel assisted procedure. Adult patients with benign or malignant thyroid disease and normal function will be included. Patients with giant goiter, hyperthyroidism, non differentiated thyroid carcinoma, locally invasive tumors, neck dissection, previous neck radiotherapy or chemotherapy, video assisted surgery and severe comorbidities will be excluded. calculated sample size was 280 patients. Outcomes will be assessed by an independent monitor. All centers will made a previous standardization of surgical procedures.