The rate of complications during thyroid surgery has decreased because of better instrumentation, illumination, and surgical expertise. Despite these improvements, certain patients, those requiring reoperation, those with invasive cancers or with numerous nodal metastasis or recurrent tumors, and those with large substernal goiters have a low but appreciable risk for complications. When planning a thyroid operation, one should perform the operation that corrects these problems and decreases the risk for complications. Localization of at least one parathyroid gland is essential. No surgical procedure can be done, however, without a risk of complications. To decrease these possible risks the surgeon should understand the embryologic development of the thyroid and parathyroid glands, the anatomical position of key structures, and use meticulous operative technique. Experience in performing thyroid operations is essential for the best outcome with the fewest complications.