Stored seeds can be invaded by various Aspergilus spp. depending upon the their moisture content. The species have a well defined lower limit of moisture content below which they cannot penetrate the seed. The infection process initiates when seeds are in equilibrium wíth relative humidity of at least 75%. The seed temperature determines the rapidity of infection, optimum being 25 to 350C for most species. The first effect this infection is weakening followed by death of the embryo. The interaction of seed moisture, seed temperature and other factors that determine the seed infection by Aspergillus spp. during storage are discussed.