Environmental Health Project, a reproductive and child health improvement program of USAID/India focusing on urban areas, has carried out several city based slum identifying and assessment exercises. Figure I depicts the process adopted. Data was collected from slums against the developed criteria by teams of trained people. A ranking key (Table II), assessment criteria for differential vulnerability was developed denoting the levels of conditions within each criterion. A score of 0-2 was given to each criterion, with a score of 0 on the criteria denoting vulnerable condition, and a maxi-mum score of 2 showing a fairly better off condition. The total scores were distributed in three categories: Less vulnerable slums, moderately vulnerable slums and highly vulnerable slums. Slums were thus classified in these three categories depending on their cumulative score based on the assessment on each criterion. The results were triangulated and refined in meetings with various stakeholders to arrive at verified, largely accurate information.