Tomato spotted wilt virus (TSWV) was detected in tomato leaf and fruit samples collected from Varamin region in Tehran province using indicator test plants including Petunia hybrida, Nicotiana glutinosa, N. tabacum cv. Samsun NN, N. clevelandii and N. benthamiana and serological tests. Small browinsh local necrotic lesions appeared on P. hybrida leaves 2-4 days post-inoculation. Systemic symptoms included concentric ring spots on leaves, stem necrosis, wilting and tissue collapse of plants 7-10 days following the inoculation. Among 145 tomato samples collected from Ghazvin, Hashtgerd, Karaj, Malard, Shahriar and Varamin in Tehran province, only Varamin samples were infected with TSWV using ELISA, DIBA and SSEM. TSWV host range specificity and symptom expression were tested on Capsicum annuum L, Chenopodium amaranticolor L, Citrullus vulgaris L, Cucumis melo var. inodorus, C. melo var. reticulatus, C. sativus L., Lycopersicon esculentum Mill., Phaseolus vulgarisL,. Solanum melongena L. and S. tuberosum. Typical symptoms on these plants included concentric ring spots, chlorosis, vein clearing, tissue necrosis, stunting and local lesion formation. Antiserum prepared against a partially pudfied TSWV preparation cross-reacted with TSWV-infected tomato samples.