Removal of all thymic tissue is the goal of surgical treatment of myasthenia gravis. In this report we describe an operation that predictably achieves that goal in most patients. The results of surgical-anatomic studies in 50 consecutive specimens obtained by this technique indicate that an en bloc transcervical-transsternal "maximal" thymectomy is required to ensure removal of all available thymus in all patients. This procedure is recommended for all patients undergoing thymectomy in the treatment of myasthenia gravis with or without thymoma and in the treatment of thymoma with or without myasthenia gravis.