Abstract: Tomato and Cucurbits viruses diseases are the major production constraints in worldwide. A survey was conducted to determine the incidence some of the most important viruses infecting tomato and Cucurbits naturally in the major growing areas in the southeast of Iran. A total of 962 symptomatic leaf samples (542 tomato and 420 cucurbits) were surveyed for virus infection by Enzyme-linked Immunosorbent Assay methods (ELISA) viz, double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) and triple antibody sandwich ELISA (TAS-ELISA). This survey revealed infection of cucurbits to ZYMV, WMV-2, CMV and CGMMV and tomato to ToMV, TSWV, TYLCV and PVY° and CMV in Southeast of Iran. TYLCV with incidence of 28.9% was the most important restriction factor in greenhouse and field-grown tomato. ZYMV ZYMV and CMV-2 was identified in all four cucurbits and prevalence of ZYMV (19.7%) is much stronger than the one of CMV-2 (8.8%). The results showed a relation between TYLCV infection and sowing date for greenhouse-grown tomato. Infections were less in early sowing date (End of July) than late sowing (First of February on forward). To our knowledge, this is the first report of serological detection of PVY° on tomato in Iran and ZYMV and CGMMV on cucurbits in Southeast of Iran.