Potato virus X (PVX) is one of the most important potato diseases that causes significant losses in potato crop worldwide. To identity the distribution and host range of different Iranian Potato virus X (PVX) isolates, 1393 symptomatic samples were collected from potato fields in seven provinces of Iran (Kerman, Hamadan, Hormozgan, Esfahan, Fars, Ardebil, north Khorasan, east Azarbaijan and west Azarbaijan provinces) during 2009-2011. Double antibody sandwich ELISA (DAS-ELISA) test was used for detection of PVX in infected samples. The result of this study indicated that percentages of infected samples were 15.2, 5.5, 4.8, 2.7, 1.3, 1.2 and 0.8 percent in Kerman, West Azarbaijan, East Azarbaijan, Ardebil, Fars, Esfahan and Northern Khorasan provinces, respectively (maximum and minimum percentages of infected samples belong to Kerman and north Khorasan provinces with 15.2% and 0.8%, respectively). To study the host range of PVX isolates, several ELISA positive samples were chosen for mechanical inoculation on test plants from three families Solanaceae, Chenopodiaceae and Cucurbitaceae. The results showed that none of the Iranian isolates were able to infect test plants from families Chenopodiaceae and Cucurbitaceae as well as solanaceous plants such as Datura maxima and Nicotiana tabacum cv. Turkish. With the exception one isolate (KER.LA.2), all Iranian PVX isolates caused mosaic, blistering, vein clearing and vein banding on test plants including D. stramonium and other tobacco varieties such as N. glutinosa, N. tabacum var Samsun NN., N .debneyii and N. clevelandii. Whereas only one isolate (from Bardsir region in Kerman province) caused sever blistering, deformation, curling and necrosis on the leaves of the test plants.