While the current system of investment treaty arbitration has definitely improved upon the “gunboat diplomacy” used at times to address disputes between states and foreign investors, there are signs that reform is needed. Increasingly, states and investors express concerns regarding the costs associated with the arbitration process; some states are refusing to comply with arbitral awards; other states now hesitate to sign new bilateral investment treaties; and citizens have begun to engage in popular unrest at the prospect of investment treaty arbitration. As a result, both investors and states are advocating for the use of mediation to supplement investor-state arbitration. This paper explains how mediation could be used in the investor-state context.