Simpson-Golabi-Behmel syndrome (SGBS) is a rare genetic disorder that is characterized by the overgrowth of various parts of the body. We present a unique case of a young man with SGBS associated with pituitary insufficiency. This association has not been described yet in the literature. The patient was diagnosed with SGBS at 12 years, which was further confirmed through genetic testing (de novo nonsense mutation of the GPC3 gene). At the age of 18, the patient consulted for alteration of the general condition with asthenia. Laboratory evaluation revealed pituitary insufficiency consisting of central hypothyroidism associated with partial secondary adrenal insufficiency. The pituitary MRI was unremarkable. So far, Pituitary insufficiency has never been described in SGBS cases. To our knowledge, this is the first case reported in the literature.