During 2001 and 2002 growing seasons, different irrigated fields were surveyed in East Azarbaijan Province. Infected plants with symptoms such as seedling damping off, crown and root rot, and foliar blight were collected. Samples were washed in running tap water and cultured on CMA+PARPH. Baiting method used for isolation of the fungus from soil. Isolates were identified on the basis of morphological and some physiological characteristics. Forty two isolates belonging to six species were identified. The species were: Phytophthora capsici from pepper and squash crown, root and stem, and tomato root; P. cryptogea from egg plant crown and root; P. drechsleri from cucumber crown, root and stem, and tomato root; P. megasperma from broad bean (soil) and alfalfa root, and P. nicotianae from sugar beet, bean, cucumber, egg plant, lettuce and squash root, pepper crown and root, and tomato root and fruit. Isolation of P. drechsleri from tomato and P. nicotianae from cucumber, pepper, lettuce and been was new for Iran. Pathogenicity tests using representative isolates of each species were conducted.