3-Trifluoroacetylpyridine adenine dinucleotide has been synthesized enzymically in two steps. The first step involved forming a glycosidic link via the ring nitrogen of 3-trifluoroacetylpyridine to ribose-5-phosphate by reaction of 3-trifluoroacetylpyridine with 5-phosphoribosyl pyrophosphate, catalyzed by nicotinamide phosphoribosyl transferase. The resulting mononucleotide was allowed to react with adenosine triphosphate in the presence of NAD pyrophosphorylase to yield the NAD analog, trifluoroacetylpyridine adenine dinucleotide. The analog behaved as an inhibitor of several NAD-dependent dehydrogenases, but it did not act as a substrate.