Spontaneous regression of pituitary tumours are rare and can be due to tumour ischaemia, pituitary apoplexy, or lymphocytic hypophysitis. We report a case of a 32-year-old female, who presented with symptoms and signs of extrasellar pituitary enlargement and hypothyroidism. MRI revealed a pituitary mass that spontaneously regressed after a month, with complete resolution of symptoms. Not all pituitary tumours require surgical intervention especially in the case of autoimmune lymphocytic hypophysitis.