Two pot trails were consummated in the nursery of Orman Botanical Garden, Giza, Egypt, during the two consecutive seasons of 2003/2004 and 2004/2005, in order to find out the effect of pre-sowing gamma irradiation on some germination and chemical traits of the four palms: Livistona chinensis, Phoenix canariensis, Sabal peregrina and Washingtonia fillifera seeds from certain mother plants were soaked for 24 hours in a tap-water, then irradiated with gamma rays at 0.0, 5.0, 10.0, 15.0, 20.0, 25.0, 30.0 and 35.0 Kr, (dose rate= 2.37 rad/sec.) during both seasons. It could be concluded that the seeds of Canary Island palm and Washingtonia showed good germination characters in response to all the studied irradiation doses, however, the 15 Kr. dose for the first mentioned palm seeds and the 10.0, 15.0, and 20.0 Kr. doses for the later one, resulted the best germination traits expressed as the highest germination percentage (G%), germination rate index (G.R.I), seed viability (S.V), velocity  co-efficient (V.C) and high indole content and total sugars%, in seeds as well as the quickest germination time and mean time to 50% germination, but the least total phenols content in seeds. The 15.0 Kr. irradiation and more and the 25.0 Kr. and more were lethal to seeds of Livistona and Sabal, respectively, whereas the  5.0 Kr. gamma irradiation dose gave the best G%, G.R.I, S.V., V.C., indoles content and total sugars% in seeds and the speedest germination time and mean time to 50% germination, but the lowest content of total phenols in irradiated seeds.