There has been a dramatic development in the treatment of pituitary adenomas during the last two decades. The main factors which led to this development were the introduction of transsphenoidal surgery, the development of new imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) and the introduction of newer dopaminergic agents. Present status of the treatment of pituitary adenoma is reported here. This report is based on the experiences of 381 cases of pituitary adenomas treated at the Department of Neurosurgery, Hiroshima University School of Medicine within the last 16 years. There are some problems which have to be solved in order to achieve further development in the treatment of pituitary adenomas. Our experience in this field and a need for future development are listed below. 1) The transsphenoidal adenomectomy gives high cure rates in cases of micro and expansive prolactinomas and growth hormone secreting adenomas. 2) Results of the transsphenoidal surgery in cases of ACTH secreting adenomas is not satisfactory. In order to get higher cure rate, a more elaborate operative techniques and an introduction of more effective drug therapy are needed. 3) Further safety and curability in pituitary surgery will be achieved by the exploitation of new imaging modalities such as MRI.