Among pituitary tumors, prolactin (PRL)-secreting pituitary adenomas are by far the most frequent ones. The development of symptomatic hydrocephalus due to a pituitary adenoma is an exceptional event. The authors describe a 37-year-old man who had a pituitary adenoma associated with obstructive hydrocephalus that was managed by endoscopic transnasal transsphenoidal surgery. Postoperative CT and MRI scans showed resolution of the obstructive hydrocephalus and the foramen of Monro was open. Postoperatively, the patient had visual and headache improvement. Subsequently, the patient is a candidate for cranial surgery or medical therapy to complete the treatment. The present case highlights the fact that pituitary adenomas with obstructive hydrocephalus should be distinguished from other tumors especially colloid cysts.