Al-MCM-41 (Mobil Composition Mater) (Si/Al = 25) molecular sieve was synthesized hydrothermally and 20 and 40wt% phosphotungstic acid (PW) was supported on it. The materials were characterized using XRD, pyridine adsorbed FT-IR, P-31 and H-1 MAS NMR techniques. Catalytic performance of the materials was examined in the liquid phase condensation of resorcinol and ethyl acetoacetate, 7-Hydroxy-4-methylcoumarin was the only product observed in this reaction. The results revealed that 20wt% PW/Al-MCM-41 is found to be more active than other catalysts. The reaction parameters were optimized to obtain high selectivity of the desired product at maximum resorcinol conversion. The reaction was also performed with substituted phenolic derivatives and ethyl acetoacetate in order to realize the substituent effect. (c) 2008 Elsevier B.V. All rights reserved.