The thymus is an important organ of the immune system and its dysfunction can drastically affect a patient’s quality of life. The thymus grows until the third year of age and then involutes during puberty. Thymomas are relatively rare and usually indolent tumors that present indistinctly and with subtle symptoms. Half of patients with cortical thymoma develop myasthenia gravis, while 15% of patients with myasthenia gravis have thymomas. Clinical diagnosis of thymoma is sufficient for planning tumor excision, complete surgical resection, or complete thymectomy is the optimal solution. Thymus removal plays an important role in myasthenia gravis because it has been proven that there is a significant clinical improvement in some patients after removal of a tumor of the anterior mediastinum. With the development of minimally invasive surgery, video-assisted thoracoscopy (VATS) has shown as an excellent alternative to classical sternotomy procedures. The role of the nurse is of great importance in the preoperative preparation, during the operation, and in the postoperative care, given that she is constantly with the patient. Caring for a patient with a thymectomy requires the expert knowledge of the nurse, recognizing any changes in the patient, responding to complications, and the nurse is obliged to provide the best care to the patient with her knowledge and skills. This paper describes the thymus as an organ, the diseases that can develop, diagnosis and surgical treatment, and the tasks of the nurse in the process of patient care that has undergone surgery to remove the thymus.