A series of N1-propanoyl-3,5-diphenyl-4,5-dihydro-(1H)-pyrazole derivatives were synthesized and assayed as inhibitors of MAO-A and MAO-B isoforms. Most of the tested compounds showed inhibitory activity with micromolar values and MAO-A selectivity. In addition a computational work was carried out on the most selective compound 3b to highlight the most relevant interactions in the mechanism of recognition within both the MAO-A and the MAO-B enzyme active sites.