Community-level physiological profiling (CLPP) is a technique which offers an easily applied protocol yielding information regarding mixed microbial community function and functional adaptations over space and time. Different communities can be compared and classified based on sole carbon source utilization patterns (CSUPs) gathered using BIOLOG™ microplates. One of the most challenging aspects associated with the CLPP method is in the data analysis. This chapter describes the relatively simple CLPP laboratory protocol and provides a detailed description of different data analysis techniques.