A new diarylnonanoid isolated from Myristica ceylanica was established as demethyldactyloidin by spectroscopic evidence and its chemical conversions to methyldactyloidin and diacetyldemethyldactyloidin. Three other diarylnonanoids, an arylalkanone, two lignans and isoflavone which are new to the species were also isolated from the same extract. Structures of these compounds were identified by comparison of the spectral data with previously reported compounds from other Myristicaceae species.