A retrospective study of 103 thymectomies examines the effects of the integration of surgical and medical therapy in patients affected by myasthenia gravis accompanied by thymoma. An extended thymectomy via a median longitudinal sternotomy was used in 102 patients. The operative mortality was 4.85% (5/103 patients), the 10-year survival rate was 78% with a recurrence rate of 3.06% (3/98). Neoplastic infiltration and postoperative radiotherapy did not influence the survival rate. There was no correlation between a preoperative Osserman's class better than III and postoperative outcome. The improvement of medical treatment, and anaesthesiological and intensive care techniques resulted in a decrease of the operative mortality and long-term death rate during the last 10 years of our 20-year series. Extended thymectomy via sternotomy is the best intervention in patients with myasthenia gravis associated with thymoma judged by the low operative mortality and the favorable 10-year survival rates.