En este trabajo se estudia la sintesis de 7-hidroxi-4-metilcumarina utilizando acido de Wells-Dawson (H6P2W18O62.24H2O), masico y soportado, como catalizador. Este heteropoliacido, usado en condiciones de catalisis heterogenea, es activo y selectivo para la reaccion entre el resorcinol y el acetoacetato de etilo. Las reacciones fueron efectuadas empleando tolueno como solvente. El acido de Wells-Dawson masico mantiene su actividad catalitica despues de tres ciclos de reaccion consecutivos, mientras que en la muestra soportada se observa una desactivacion tras el segundo ciclo de reaccion. La tecnica informada representa una alternativa limpia para la industria quimica. Palabras clave: Heteropoliacidos, Wells-Dawson, cumarinas, catalisis heterogenea, quimica verde. Abstract In this work, it is studied the synthesis of 7-hydroxy-4methylcoumarin using Wells-Dawson acid (H6P2W18O62.24H2O), bulk and supported on silica, as catalyst. This heteropolyacid, used in conditions of heterogeneous catalysis, is active and selective for the reaction of resorcinol with ethyl acetoacetate. Reactions were carried out using toluene as solvent. Bulk Wells-Dawson acid keeps its catalytic activity after three consecutive reaction cycles, meanwhile in the supported sample a deactivation after of second cycle is observed. The reported technique is a clean alternative for the chemical industry. Keywords: Heteropolyacids, Wells-Dawson, Coumarins, Heterogeneous Catalysis, Green Chemistry.