Through this research, we shows a study on the identification of poverty in a great city with over a million of habitants -and featured with a radical violence which costs 32000 deaths-and analyze vulnerability with homeless and poor people in the municipality of Ciudad Juarez -a largest city in México, the seventh most largest-, trying the questionnaire used for the study, with fuzzy logic techniques. With this new method of treatment about questionnaires using fuzzy logic techniques, we can obtain the equivalent response of a specific group, as well as membership and uncertainty of it. This will reduce the subjective interpretation of the pollsters, favoring decision to propose public policies related to improving the quality of life of people in this society.