Mersin is the second most intensive tomato-producing city in Turkey, with a harvest of 470,239 tons of tomatoes. Tomato is produced in plastic greenhouses in coastal areas of Mersin in winter, and open fields on the plateau are used for summer growth. In 2015, plastic greenhouses and open fields in Mersin city were surveyed to screen for tomato bacterial diseases. From surveys carried out in April-August 2015, it was determined that bacterial canker caused by Clavibacter michiganensis subsp. michiganensis (Cmm) was the most destructive tomato bacterial disease in open fields. However, typical symptoms of bacterial speck caused by Pseudomonas syringae pv. tomato (Pto), stem soft rot caused by Pectobacterium caratovorum (Pca), pith necrosis caused by Pseudomonas viridiflava (Pvir) and bacterial canker caused by Cmm were observed in plastic greenhouses between September 2014 and May 2015. Bacterial speck disease was widespread in plastic greenhouses. In total, 63 bacterial strains were isolated from diseased plant material, and all strains were pathogenic on tomato ` Alsancak'. The strains were identified as Cmm, Pto, Pca and Pvir according to morphological and biochemical properties by using LOPAT tests (L, levan production; O, oxidase reaction; P, pectolytic activity on potato slices; A, arginine dihydrolase activity; T, hypersensitive reaction on tobacco), fatty acid methyl ester (FAME) analysis and PCR with species-specific primers (except for Pvir). Visits to open fields and plastic greenhouses in Mersin are under way in further production season of tomatoes.