Most pituitary tumours are non-invasive, benign adenomas that remain confined to the sella turcica. Some of them recur, have a rapid growth rate, and invade surrounding tissues. These adenomas, considered aggressive pituitary tumours, are difficult to manage and present problems due to incomplete resection. A pituitary carcinoma is diagnosed when craniospinal and/or systemic metastases are documented. Treatment options for pituitary adenomas are surgery, radiation and drugs. Recent publications report the efficacy of temozolomide in the treatment of aggressive pituitary adenomas and carcinomas. Indications for, results with, and side effects of temozolomide therapy in aggressive pituitary tumours and pituitary carcinomas are reviewed here. Alternative treatment options for resistant or recurrent pituitary tumours are also discussed.