The present work was carried out in Jazan region. The region of Jazan in being in the South-Western part of Saudi Arabia between longitudes 42⁰  and 43.8⁰ and latitudes 5, 16^o and 17^o, and is bounded on the south and east of the Republic of Yemen, Asir area in the north and the Red Sea in the west.  The results showed that there are four families of poisonous snakes "Proteroglyphous" living in Jazan region. They are: Family Atractaspididae, Elapidae, Viperidae and  Hydrophiidae . This work aimed to unveil ecological problems and throw light on diversity of poisonous snakes in Jazan region and the danger of these species to human life. Despite the fact that these snakes may be harmful to human life in some cases, it may also be useful to him in many aspects of life. Since there are no enough studies on the animal species in the region, this study came to identify the diversity of this animal group. There is no doubt that  the study of these species and identifying them will provide some solutions that could make this group as an endless source of biodiversity and at the same time, this study provides information on the feasibility of protection of this species in this region. Discussion of ecological and geographical affinities of this taxa and taxonomic keys of different types in order to facilitate the process of identification will be provided.