This chapter provides detail description of Pituitary tumours, sellar and suprasellar lesions. Chapter has 5 well illustrated diagrams and pictures. Pituitary adenoma, lesions of the sella turcica, adenomas of specific cell type, growth hormone cell adenoma, prolactin cell adenoma, adenoma producing growth hormone and prolactin, WHO classification of pituitary adenomas, adrenocorticotropic hormone cell adenomas, null cell adenomas, invasion and malignancy in pituitary adenomas, markers of biological behavior of pituitary adenomas, molecular pathology: oncogenes and tumor suppressor genes, craniopharyngioma, pituicytoma and granular cell tumor, spindle cell oncocytoma of the adenohypophysis, post-irradiation sarcoma, non-neoplastic lesions of the sella turcica are described in detail. 3 tables are included to highlight lesions of sella turcica, WHO classification of pituitary adenomas and ultra structural features of pituitary adenomas. 57 references are included at the end of the chapter to facilitate further reading.