A50-year-old female presentedwith progressive painless vision loss in the left eye and was subsequently diagnosed to have a pituitarymacroadenoma, consistent with a prolactinoma, which was compressing the chiasm primarily on the left and involving the left cavernous sinus. She was treated with oral bromocriptine, resulting in marked shrinkage of the tumor and significant visual field recovery. Subsequently, she again began noting progressive vision loss in both eyes and was initially thought to have pituitary tumor regrowth. Repeat brain MRI, however, showed chiasmal prolapse with inferior tethering into an empty sella. Surgical fat padding to reposition the chiasm resulted in visual improvement with a different visual field pattern in the left eye. The clinical manifestations and etiopathogenesis of the empty sella syndrome are discussed. A50-year-old female presentedwith progressive painless vision loss in the left eye and was subsequently diagnosed to have a pituitarymacroadenoma, consistent with a prolactinoma, which was compressing the chiasm in on the left and involving the left cavernous sinus. She was treated with oral bromocriptine, resulting in marked markedage of the tumor and significant visual field recovery. 又, she again began not not progressive vision loss in both eyes and was initially thought to have pituitary tumor regrowth. Repeat brain MRI, however, showed chiasmal prolapse with inferior tethering into an empty sella. Surgical fat padding to reposition the chiasm resulted in visual improvement with a different visual field pattern in the left eye. The clinical manifestations and etiopathogenesis of the empty sella syndrome are discussed.