Background: Thyroid surgery had been and was the most common endocrine surgical operations.An accurately performed operation on thyroid gland requires both experience and technical ability and is considered by many to be at the zenith of endocrine surgery.When thyroid operations are performed without sufficient interest, training, or experience the incidence of preventable complication is high.The mortality rate of thyroidectomy as reported in several large series approaches zero.The morbidity of thyroidectomy, however continues to be a matter of concern.Recent research suggests that surgeons may differ in their ability to perform this refined surgery with sufficient care. Aim of Study:The aim was to to evaluate of postthyroidectomy complications in autoimmune thyroid diseases versus nodular thyroid diseases. Patients and Methods:The study was a prospective randomized study which was done over 100 patients suffering from thyroid disease into two groups, group (I) 50 patients presented with autoimmune thyroid diseases, group (II) 50 patients presented with nodular thyroid diseases.The patients was subjected to total thyroidectomy under general anesthesia which was performed in General Surgery Department of Faculty of Medicine, Menofia University in the period from April 2019 to May 2020.Operative time was reported from start of skin incision till closure of the wound.The two groups were followed-up for one month post-operative which is the end point of the study.Results: In cases of group (I); during operations there was difficulty dissection in 30 cases (30/50, 60%), excessive bleeding in 35 cases (35/50, 70%), nerve damage in 5 cases (5/50, 10%), tracheal damage in one case (1/50, 2%).While in group (II) difficulty dissection in 5 cases (5/50, 10%), excessive bleeding in 2 cases (2/50, 4%), nerve damage only in one case (1/50, 2%).And statistical analysis revealed the predominance of operative difficulties and complications in group (I) than in group (II) (p=0.01).