Three cases with a pituitary cystic mass that spontaneously disappeared were discussed. Common characteristics of these 3 cases were presence of headache, cystic mass, spontaneous disappearance, and no recurrence. Based on clinical course, MRI findings such as cystic mass with ring enhancement, no calcification, and displacement posteriorly of the normal pituitary gland, and previous reports, these 3 cases were diagnosed as an equivocal Rathke's cleft cyst. We suggested that operative indication in an equivocal Rathke's cleft cyst, even though it was symptomatic, should be decided after sufficient follow-up, because there may be a possibility of spontaneous reduction or disappearance like our cases.