Magnetic resonance imaging is the fundamental imaging tool for the evaluation of tumors and other lesions of the pituitary gland and infundibulum. Abnormalities may arise within the pituitary itself, from vestigial embryologic remnants, or from surrounding tissues. Correct diagnosis rests on accurate assessment of lesion location, imaging appearance, and clinical presentation. This article reviews the radiologic evaluation of lesions within the sella and suprasellar cistern, focusing on common masses and pseudomasses of the pituitary and sellar region that neurosurgeons are most likely to encounter in clinical practice.