As of the 1960s the international law of foreign investment has been characterized by the emergence of international arbitration as the preferable means of settling investment disputes, and the increasing recognition by treaty law of private investors’ ability to espouse therein their international claims directly against the host States. Investment arbitration has, however, advanced impressively in the mid-twentieth century, thanks also to an ever-growing network of international investment agreements, indicating international arbitration as a means for resolution of investor-State disputes available to national investors of the Contracting Parties. The chapter provides a general overview of investment treaty arbitration and its features as well as ICSID and non-ICSID arbitration more specifically. Furthermore, procedural issues, the award and the post-award procedure are explained. Finally, the chapter also looks at new approaches to investment dispute settlement such as the Investment Court System of the European Union or the proposal for a multilateral investment court.