Concept-oriented terminologies require the user to combine terms, making them awkward for their direct use as a documentation tool. Therefore, classification systems are needed to serve as interface terminologies between the user and the reference terminology used to organize the computer database system. Whether nursing classification systems provide sufficient granularity to adequately capture nursing practice is controversial. In addition, no nursing classification systems have been designed specifically for or evaluated in the critical care setting. The purpose of this study was to evaluate the ability of the Clinical Care Classification (CCC) to represent data in an intensive care setting and to provide recommendations for the expansion of this classification for its use in critical care documentation.