A new prenylcoumarin was isolated from the leaves of Murraya paniculata (Rutaceae), and its structure was elucidated as 5,7-dimethoxy-8- $[(Z)-3'- ext{methylbutan-1',3'-dienyl}]$ coumarin on the basis of spectroscopic evidence. Five other coumarins were also obtained and identified with the known compounds coumurrayin, 5,7-dimethoxy-8-(3'-methyl-2'-oxobutyl)coumarin, toddalenone, toddasin and aurapten. In recent papers1) we reported the isolation of highly oxygenated flavonoids as major constituents of an Indonesian medicinal plant Murraya paniculata (L.) JACK (Rutaceae). Further investigation of the remaining minor fractions have shown the occurrence of several coumarins. The present paper deals with the isolation and characterization of coumarin derivatives, including one new compound, from the leaves of M. paniculata of Indonesian origin.