In a field experiment in Burkina Faso, we test a "third-party performance pay" scheme for community-based organizations (CBOs). Selected CBOs are promised a variable cash grant that is proportional to changes in their local government's performance scores over a two-year period. We test if third-party performance pay (1) motivates CBOs to actively lobby for better municipal performance, (2) increases accountability and problem-awareness of municipal decision makers and (3) ultimately leads to improvements in municipal government performance. We also investigate if the incentive scheme had any unintended consequences for the internal functioning of the beneficiary CBOs.