This study aimed to identify the bacterial pathogens associated with abnormal symptoms in farmed mud crabs (Scylla paramamosain) in Ca Mau province. There were 161 isolates of bacteria obtained from blood, hepatopancreas and muscle of 202 collected mud crabs using TCBS and TSA medium supplemented 1.5% NaCl. A total of 11 representative isolates based on morphological features were identified using 16S rRNA sequencing. There were six different species including Vibrio parahaemolyticus, Vibrio alginolyticus, Vibrio harveyi, Photobacterium damselae, Shewanella algae and Staphylococcus saprophyticus were identified, in which Vibrio spp. were the most dominant (63,63%). These bacterial species, except S. algae, have been documented as causative agents of bacterial diseases in mud crabs. Furthermore, the phylogenetic analysis indicated that Vibrio species isolated in the present study were closely related to each other as well as the minimal difference between isolates and other selected reference strains.