Increasingly national statistical agencies are being called upon to provide high quality data on a regular basis, to be used by governments for evidence-based policy development. Poverty Reduction Strategy Papers (PRSPs) give impetus to this, and bring a prerequisite for comprehensive "poverty diagnosis." Often the data that are required are not available, or are incomplete while the concepts that are to be used may be ambiguous or require adaptation to local conditions. The poverty analysis of Lesotho in this article represents a contribution towards the emerging culture of evidence-based policy-making in developing countries in that it explores changes in key poverty-related social indicators. Techniques for dealing with poor data are discussed and an approach to developing a poverty threshold adapted to the local conditions of Lesotho is described.