Thymoma is the most frequent type of tumor in the anterior-superior mediastinum. The presentation of thymomas is variable; most are asymptomatic and others present themself with local compression syndrome or parathymic syndrome; rarely thymomas appear as an acute emergency. Surgery is the treatment of choice for thymic tumors and complete resection is the most important prognostic factor. Surgery with adjuvant radiation is recommended for invasive thymoma. The anaesthetic management of patients with mediastinal thymoma undergoing thymectomy is associated with several risks related to potential airway obstruction, hypoxia and cardiovascular collapse. Patients at high risk of perioperative complications can be identified by the presence of cardiopulmonary signs and symptoms. However, asymptomatic thymomas have been occurred with acute cardiorespiratory complications under general anaesthesia. A careful preoperative evaluation of signs, symptoms, chest X-ray, CT scan, MRI, cardiac echogram and venous angiogram should be helpful to investigate neoplasm presence and the area of invasion; moreover, an adequate airway and cardiovascular management, such as performing an awake intubation in the sitting position, allowing spontaneous and non-controlled ventilation, a rigid bronchoscope available and a standby cardiopulmonary bypass, is suggested to prevent the main life-threatening cardiorespiratory complications.