Arguing from the premise that the basic problems facing the water and wastewater (W&WW) sector are institutional in nature, this document provides a set of procedures for diagnosing deficiencies in W&WW institutions. The guidelines are based on team field investigation procedures which identify, define, and verify institutional performance using functional categories which were developed through field analyses of W&WW institutions in two developing countries. In order of relative importance, the categories are: (1) organizational autonomy; (2) top leadership; (3) management and administrative systems; (4) commercial and consumer orientation; (5) technical capability, along with staff development and maintenance; and (6) organizational culture, along with interactions with key external institutions. To ensure rigor and balance, it is suggested that the analysis take place in five steps: data analysis by individual team members and then by the team as a whole; synthesis of findings, including the weighting of different dimensions; preliminary presentation of the analysis to a review committee; and reverification of findings prior to final presentation. The intended end result of the procedure is a defined profile of institutional strengths and weaknesses which can be used for designing institutional improvement projects.