A series of N-substituted-3-[(2′-hydroxy-4′-prenyloxy)-phenyl]-5-phenyl-4, 5-dihydro-(1H)- pyrazolines were synthesized and tested on human monoamine oxidase-A and-B isoforms. Structure–activity relationships and molecular modelling showed that some substitutions, such as benzyloxy or chlorine atom, improve the best interaction with active site of hMAO-B.