The Anti-Corruption Protocol to the United Nations Convention against Corruption (APUNCAC) would establish aggressive measures to fight corruption and impunity, including a body of UN inspectors empowered to investigate charges of corruption, dedicated anticorruption courts, and provisions designed to fight money laundering. A theory-based realist evaluation (TBRE) approach was employed to assess program assumptions. The design illustrates how theory-based realist evaluation may be adapted and used to evaluate governance initiatives that are not easily evaluated using conventional strategies.