Disclosure laws for politicians exist in over a hundred countries. But can public disclosures about politician performance and qualifications influence electoral accountability in settings characterized by weak institutions and less educated populations? In the run-up to the 2008 elections in Delhi we implemented a field experiment where we provided slum dwellers with newspapers containing report cards giving information on candidate qualifications and legislator performance obtained under India’s disclosure laws. Access to report cards increased voter turnout; this effect is larger when incumbent performance is worse. We also observe reductions in the incidence of cash-based vote buying and electoral gains for better performing incumbents. Finally, we observe significant voter sophistication in the use of information – voters make comparisons across spending categories and candidates to overcome political agency problems and reward better performing incumbents.