Rathke cleft cyst is thought to arise from incomplete obliteration of the lumen of Rathke pouch. The cells of the anterior pituitary lobe, from which pituitary adenomas develop, are also derived from the cells of Rathke pouch. Although Rathke cleft cyst and pituitary adenoma have a shared ancestry, they rarely occur coincidentally. Rathke cleft cysts have been found incidentally in 11%-33% of post-mortem examinations, and were associated with 1.7%-2.1% of the pituitary adenoma cases. These coexisting lesions are difficult to diagnose pre-operatively due to the variable signal intensity and position of the Rathke cleft cysts. Treatment of these lesions involves surgical resection to decrease mass effect and medical management to normalize hormonal imbalances. To our best knowledge, only 42 cases of Rathke cleft cyst with a coexisting pituitary adenoma have been reported in the English or Japanese literatures, but none of the coexisting pituitary adenoma is gonadotropin producing. We would like to report a case of Rathke cleft cyst with a coexisting gonadotropin producing adenoma that was successfully treated by endoscopic endonasal transsphenoidal approach with the removal of the sellar lesion and temporary hormone replacement.