This paper presented a multicriteria assessment model for evaluating the performance of combined heat and power systems. Interval-valued intuitionistic fuzzy numbers were used for representing the subjective and imprecise assessments of the decision maker in evaluating the relative importance of the criteria, and the performance of individual combined heat and power systems. An effective algorithm was developed based on the concept of ideal solutions for calculating the overall performance index, for each combined heat and power system across all criteria. An example was presented to demonstrate the applicability of the multicriteria assessment model, for dealing with real world combined heat and power system performance evaluation problems.