The thyroid gland, or simply the thyroid, is an endocrine gland located in the anterior region of the neck. It secretes two very important hormones, triiodothyronine (T3) and thyroxine (T4) which regulate the function of almost all organs in the human body. Thyroid is relatively small, but very often affected by pathological processes that are manifested as nodes in the gland. Benign thyroid nodess include goiter, inflammation and benign tumors, with dominant clinical signs of hypothyroidism or hyperthyroidism. The most common malignant processes are epithelial tumors (carcinomas) incurred as a result of malignant alteration of follicular epithelium or even of parafollicular C-cells in case of medullary carcinoma. All of the thyroid cancers are treated surgically. Extensiveness of the surgery depends on the stage of the tumor, which is provided from the TNM classification based on diagnosis. Most commonly used operative technique is lobectomy which is indicated for the treatment of all benign tumors, and also malignant tumors of low stage. For all the other malignancies, the treatment of choice is a thyroidectomy with or without neck dissection depending on intraoperative findings of regional metastatic disease. When excluding rare, non-differentiated types of tumors, (anaplastic and medullary), treatment of the most common types of cancer, papillary and folliculary is generally successfull with a very high survival rate. Papillary carcinoma has the best prognosis with survival rate of 100%. Follicular thyroid carcinoma is slightly less curable with survival rate of >70%. Undifferentiated tumors have great metastatic potential and are difficult to treat. Five year survival rate of patients with medullary carcinoma is less then 50%. Anaplastic thyroid cancer has a very poor prognosis due to its aggressive behavior and resistance to any treatment. Luckily, it is extremely rare.