New electron deficient tin(IV) porphyrins were used as efficient catalysts for the reaction of 4,4'-methylene-bis-(4-phenylisocyanate) (MDI), with L-leucine anhydride cyclodipeptide (LAC) and polyethyleneglycol-400 (PEG-400) and the results were compared with those obtained in the presence of a commercial catalyst, dibutyltin dilaurate (DBTDL). Molar ratio of catalysts to MDI, polymerization reaction time, viscosity, and yield of the resulting poly(ether-urethane-urea)s (PEUU) were compared in the presence of different catalysts. The rate of N = C = O conversion in the presence of each catalysts under the same reaction conditions was also compared and followed by FT-IR N = C = O absorption band. FT-IR, GPC, and viscosity studies have shown that tin(IV) porphyrins afford higher viscosity and reaction progress. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012