Abstract:Compactness is an important property of fuzzy logic systems. It was proved that ?ukasiewicz propositional logic, G?del propositional logic, Product propositional logic and the formal deductive system L* are all compact. The aim of the present paper is to prove the compactness of the fuzzy logic system NMG by characterizing maximally consistent theories and by proving the satisfiability of consistent theories over NMG.