Policymakers use poverty maps to design and assess poverty programs. The accuracy of these maps, which is critical for targeting, depends largely on the nature of the instrument used to construct them. Recently, in response to tight budget constraints, many countries have begun to construct poverty maps based on light monitoring surveys that rely on short questionnaires. This article shows that poverty maps constructed from such surveys are not accurate and could result in substantial leakage. Light monitoring surveys do include large samples that can help to target poverty programs at subregional levels. Combining these surveys with more detailed Integrated Surveys can help researchers reduce targeting errors significantly and build improved poverty maps with finer levels of disaggregation. Copyright 2000 by Oxford University Press.