Hematopoietic stem cell transplantation (HSCT) is used for various hematologic malignancies seen in children and adults. There may be several complications before, during, and after the HSCT. Just one of them is endocrinologiccomplications, since endocrine system (particularly the pituitary gland, thyroid gland, adrenal glands, and gonads) is highly sensitive against various stress. Chemotherapy and/or total body irradiation used as preparative regimens and immunosuppressive agents (especially corticosteroids) used for the graft-versus-host disease can cause hormonal disorders. Time elapsed after the HSCT, transplantation type (autologous or allogeneic), preparative regimen choice, age, and gender determines the complications. A multidisciplinary management containing a specialist of endocrinology for these patients is preferred. In this report, we reviewed the endocrinologiccomplications that observed after the HSCT in children and adults referring to the recent literatures.