Flexible manufacturing systems (FMS) are capable of processing various parts, styles, and quantities of production in manufacturing systems. It is a quite complex process for companies to decide the appropriate FMS design as it involves multiple and conflicting criteria and multiple decision makers under various uncertainties. The fuzzy set theory offers an efficient tool to cope with vagueness and to define performance measurement of FMS in a multi-attribute group decision making (MAGDM) framework. In this study, we present a MAGDM approach based on hesitant fuzzy sets to evaluate FMS in a fuzzy environment. A practical example is provided to demonstrate the proposed methodology. In addition, the performance of the method is assessed by a comparative study and sensitivity analysis. The results of the analysis show that the MAGDM approach is a useful tool for experts in terms of evaluation of FMS.