Introduction: Vietnamese Tra fish (Pangasius hypophthalmus) have become highly appreciated by consumers in the European Union, USA, Canada, etc. and are therefore of worldwide economic importance. The availability of data in microbiological quality and safety of this fish species is however limited. Purpose: The dynamics of microbiological performance of Vietnamese processing company between large and small scale plants were evaluated from raw material until final product by microbial assessment scheme. Methods: The total of 279 samples (144 samples in large scale plant) were taken for monitoring: overall microbial quality (psychrotrophic aerobic count), hygiene indicators (E. coli and S. aureus), and relevant pathogens (Listeria monocytogenes and Vibrio cholerae). Results: The low levels of total psychrotrophic bacteria and E. coli on final products sampled from large scale plant were ca. 3 log CFU/g and below detection limit, respectively. In addition, the pathogen of Listeria monocytogenes and Vibrio cholerae was absent in all samples analysed. On the contrary, high numbers of total psychrotrophic bacteria (ca. 6 log CFU/g on fish and ca. 6 log CFU/ 100 cm² on food contact surface) were found on the small scale plant during processing. Additionally, the foodborne pathogen was present in water, hands and fish; especially the presence of L. monocytogenes on a final Pangasius product. Significance: These data are of major importance in order to provide valuable information for the local and international trade point of view in general and for the intended customers in particular.