The Port-au-Prince urban livelihoods baseline contains detailed, quantified information on the food, income and expenditure patterns of the urban poor. The assessment was conducted at a time of relative security and price stability from April to May 2009. Thus this baseline provides a picture of the urban poor as they were following the hurricanes, price rises and food riots of 2008. In conjunction with monitoring data, the baseline is a powerful tool that can be used for ongoing analysis of food and livelihood security in the slums of Port-au-Prince.