This study reviews a decade of support by the World Bank and the Inter-American Development Bank to parliaments and external audit agencies in Latin America. It underscores recent developments in development finance reflecting a broader understanding of the determinants of fiscal credibility and financial integrity. It reveals a learning curve in multilateral assistance to budget oversight institutions. It argues that there exists unexplored potential to improve the effectiveness of multilateral assistance to budget oversight institutions, including in the choice of strategies and instruments. More fundamentally, it underscores the need to tackle the underlying political economy of public finance accountability.