This monograph describes ACCION’s experiences with poverty measurement at four microfinance institutions in Latin America and the Caribbean. It explains ACCION’s research objectives and different approaches to the measurement of poverty that ACCION considered before developing its own poverty assessment tool. It also details major findings of the poverty assessments at four microfinance institutions and describes general lessons learned on the collection and analysis of poverty data. The monograph concludes by explaining how information from the poverty studies has been used at the four case study institutions.