Ralstonia solanacearum species complex (RSSC) is the main pathogen causing bacterial wilt disease in tomatoes. This study applied the colony polymerase chain reaction (PCR) technique to rapidly screen and select RSSC strains from isolated bacteria of diseased tomatoes. This method directly used bacterial colonies on the Petri plate as templates to amplify with RSSC’s specific and multiplex primers. The results showed that the Vietnamese isolates were identified as R. pseudosolanacearum, phylotype I. Phylogenetic analysis of the 16S-23S rDNA sequencing also confirmed these results. Therefore, this is the first report to recognize R. pseudosolanacearum phylotype I as the cause of bacterial wilt disease in tomatoes from Danang.