Chemotherapy treatment and autologous and allogeneic cell transplantations are often complicated by the onset of metabolic and endocrine disorders. Autoimmune disorders, metabolic diseases, and hormonal dysfunctions are some of the endocrine complications observed during or after treatment with immunotherapy (mostly novel agents) and/or chemotherapy conditioning for transplantation. Although successful treatment of the underlying hematological condition often improves the dysfunction, endocrinopathies can have an impact on prognosis and are associated with poor survival; therefore, it is important to detect and treat them as early as possible. An increased incidence of cardiovascular diseases and metabolic syndrome has been observed after transplantation mostly in longterm survivors. In addition, chemotherapy and radiation along with the prolonged use of corticosteroids can contribute to the onset of thyroid and gonadal dysfunctions. The aim of this article is to describe metabolic dysfunctions occurring in patients who underwent allogeneic cell transplantation.