Abstract— The previously reported (Krasna, 1979) photoproduction of hydrogen from organic compounds in the presence of methyl viologen and platinum, catalyzed by proflavin, has now been accomplished with other photocatalysts. The acridine derivatives acriflavin, acridine yellow and acridine orange were active catalysts, whereas 9‐aminoacridine was not. The reaction was similar to the proflavin catalyzed reaction with respect to electron donor specificity and mechanism. Tris(2,2'‐bipyridine)ruthenium (II) also replaced proflavin and the reaction was similar in most respects to that catalyzed by proflavin except that rris(2,2'‐bipyridine)ruthenium catalysis was most effective at alkaline pH values. The deazaflavins, deazaribofiavin and 3,10‐dimethyl‐5‐deazaisoalloxazine, were more active than proflavin, particularly at alkaline pH values. Deazaflavins catalyzed photoproduction of hydrogen from a variety of compounds that were inactive with acridines and fra(2,2'‐bipyridine)ruthenium. This includes carboxylic acids, amines, sugars and amino acids. This system may have potential for hydrogen production as a means of solar energy conversion.