Interest in plants is increasing and much work is being carried out these days on their multipurpose uses. A great impetus has been given to this during the last 3 decades. Several publications have been made by different investigators. Large number of naturally growing plants are collected and sold at the markets. Nearly 500 plants are used for primary health care in Turkey and a 23 in Cyprus. However, not much is known about the poisonous plants. Some of these are toxic and others cause reaction. Plant poisoning lies around 6%, rurals suffer more from the consumption of naturally growing plants as compared to urban dwellers. One has to be very cautious before using these plants as the plants used for the purpose of treatment of diseases as a whole or parts thereof or consumed by the public directly could prove dangerous for the health. This paper describes ethnoecological aspects of the widely distributed major poisonous plants in Turkey and Northern Cyprus which can prove fatal if used unknowingly. Major applications and active constituents of plant taxa are outlined.