Introduction:Retrosternal goiter refers to any thyroid enlargement in which over 50% of the thyroid permanently located under the thoracic inlet or the lower pole of thyroid is not palpable with the neck in hyperextended position. Due to the increasing number of surgical procedures of retrosternal goiter, the present study was carried out to examine the symptoms, diagnosis, treatment, and treatment complications in retrosternal goiter patients.Materials and Methods:Data related to demographic data (age and gender), clinical symptoms (dyspnea, dysphagia, dysphonia, lumps in neck, and hoarseness), methods of diagnosis (computed tomography [CT], chest X-ray [CXR], ultrasonography, and magnetic resonance imaging), and postoperative complications (bleeding, early and late dysphonia, early and late dyspnea, transient and permanent hypocalcemia, transient, and permanent recurrent laryngeal nerve paralysis) were collected.Results:According to the results 71.4% of patients were women and most of the participants (67.1%) aged 45–60 years. Mass in the neck was the most frequent symptoms before surgery (88.6%). The most common incision for thyroidectomy (95/7%) was neck Collar incision. Diagnosis method in 82.9% and 17.1% of cases was, respectively, based on CT scans with CXR and CT scans with CXR and ultrasound. According to the postoperative pathologic findings, 58.5% of the cases were multinodular goiter, 22.9% were papillary cell carcinoma, 7.1% were medullary carcinoma, 5.7% were anaplastic carcinoma, 5.7% were thyroid lymphoma, and only 1.4% were thyroid adenoma. Postoperative complications occurred in 47.14% of patients. Most common complication was early transient dysphonia.Conclusion:This study recommends that retrosternal goiter should be operated early under suitable conditions, and the best diagnosis tool and best surgery methods are CT scan and surgery with collar incision, respectively.