Although pituitary adenomas and Rathke's cleft cysts have a shared ancestry, they rarely occur simultaneously. Only 32 reports involving a pituitary adenoma and a concomitant Rathke's cleft cyst were identified upon review of the literature. Most initial presenting complaints include hormonal symptoms, visual disturbances, and headache. Next to growth hormone, Prolactin was the most commonly hypersecreted pituitary hormone. Rathke's cleft cysts show variable position, size, and signal intensity on magnetic resonance imaging (MRI). Here, we report a patient with a growth hormone- secreting pituitary adenoma associated with a Rathke's cleft cyst. The mass contained two different signal intensities on MRI. The lesion was successfully removed assisted by intraoperative MRI, when the presence of both lesions was confirmed. When a non-enhancing cyst-like structure is demonstrated on imaging in a patient with a pituitary adenoma, the possibility of a coexisting Rathke's cleft cyst should be considered.