Aiming to substitute toxic synthetic fungicides, the activity of nutmeg (Myristica fragrans) essential oil (EO, obtained by hydrodistillation) was investigated against two important storage fungi-Aspergillus flavus A. ochraceus. The activity of crude nutmeg EO was investigated using poison food assay (PFA). At a concentration of 0.1%, the EO inhibited A. flavus and A. ochraceus growth by 43 and 65%, respectively. At a concentration of 0.3 %, A. flavus and A. ochraceus inhibitions were 84 and 79%, respectively. The crude nutmeg EO on fractionation by preparative TLC-bioautography presented one band from which two pure compounds were isolated by semi-preparative normal-phase high performance liquid chromatography. Myristicin and safrole were identified by nuclear magnetic resonance (¹H and ¹³C) and gas chromatography-mass spectrometry. The relative % of myristicin and safrol in the crude EO was 10.8 and 2.9, respectively, determined by gas chromatography with a flame ionization detector. The crude EO, the isolated active fraction, isolated myristicin and standard myristicin presented similar activities against the two fungi at concentrations of 0.1 and 0.3% by PFA. Based on these results it is concluded that myristicin is the major antifungal in nutmeg EO against A. flavus and A. ochraceus.