Choroid plexus papillomas are rare tumors of the central nervous system and are usually confined to the ventricular system. We illustrated a primary choroid plexus papilloma in the pituitary fossa. A 31-year-old female presented with amenorrhea and intermittent galactorrhoea, with no visual complaints in the last 2 years. Endocrine testing showed no hormone excess or deficiency of the pituitary and target glands, except for a higher prolactin level (56 ng/ml). A sharply circumscribed regular mass in the sellar region occupying the entire sella turcica and extending into the suprasellar cistern was demonstrated on MR imaging with gadolinium diethylenetriamine pentaacetic acid. The patient underwent an endonasal trans-sphenoidal approach. Complete microsurgical excision and complete preservation of the normal pituitary gland was achieved, with normal prolactin level. The histopathology showed that the lesion was a choroid plexus papilloma. Theories of the origin, the differential diagnosis, and treatment of the rare tumor are discussed.