Concomitant pituitary adenomas and Rathke's cleft cysts (RCCs) are rare. These coexisting lesions are difficult to diagnose preoperatively due to their variable signal intensity on magnetic resonance imaging (MRI) and position of the RCC. We describe three cases of coexisting pituitary adenoma and RCC, and review the relevant literature. In our cases, the RCCs were relatively large and the en plaque adenomas appeared as enhanced cyst walls on MRI examination. We also report the clinical, radiologic, surgical, and histopathologic findings of each case.