Pituitary hyperplasia is commonly present but remains largely undiagnosed in primary hypothyroidism. It is easily reversible with thyroid replacement therapy. If imaging is performed prior to biochemical evaluation, then patients may undergo pituitary surgery. We present the case of a 34-year-old female with profound primary hypothyroidism and secondary pituitary hyperplasia that resolved after thyroid hormone supplementation. We will discuss the current literature regarding pituitary hyperplasia in primary hypothyroidism in adults.