Yes. Several ATMs in Lhasa and Shigatse accept foreign cards. The Bank of China accepts Visa, MasterCard, Diners Club, American Express and Plus. The Agricultural Bank accepts Visa, Plus and Electron.
The maximum amount you can withdraw per transaction is Y 2,000 with the Bank of China and Y 1,000 with the Agricultural Bank.
There with be no ATMs or banks in many remote areas of Tibet, so please carry some cash with you when visiting these places. Check the Money and Credit Card in Tibet for more information.