The mediastinum is located from the thoracic inlet to the diaphragm between the left and right pleural cavities and contains vital structures of the circulatory, respiratory, digestive, and nervous system. Over the years, since there are no fascial or anatomic planes, anatomists and radiologists have suggested various schemes for subdividing the mediastinum and several anatomical and radiological classifications of the mediastinum are reported in the literature. The most popular of these scheme divides medistinum, for purposes of description, into two parts: an upper portion, above the upper level of the pericardium, which is named the superior mediastinum; and a lower portion, below the upper level of the pericardium. For clinical purposes, the mediastinum may be subdivided into three major areas, i.e. anterior, middle, and posterior compartments. The anterior mediastinum is defined as the region posterior to the sternum and anterior to the heart and brachiocephalic vessels. It extends from the thoracic inlet to the diaphragm and contains the thymus gland, fat, and lymph nodes. This article will review surgical anatomy of the anterior mediastinum and will focus on the surgical approch to anterior mediastinum and thymic diseases.