The aim of the present study was to preliminarily determine the occurrence and characteristics of extended spectrum beta-lactamases (ESBL)- and AmpC- producing Escherichia coli (E.coli) in fish samples collected from non-cultured and cultured fish in the Mekong Delta, Vietnam. Isolated E. coli strains were examined for the ESBL and AmpC beta-lactamases production by the use of disc diffusion tests. All positive strains were examined by PCR for the presence of the bla_CTX, bla_TEM, bla_SHV genes. The obtained results showed that: (1) A total of 90 E. coli strains were isolated from 72 fish samples. Among these, 36 (40%) strains were identified in phenotypic tests as ESBL-producing and 26 (28.9%) strains as AmpC-positive. The overall prevalence of ESBL-producing E. coli infection was 59.2%, 44.4% and 36.7% for striped catfish, red tilapia and wild fish, respectively; (2) ESBL- producing E.coli contained common beta-lactamase genes including bla_TEM (11 isolates), bla_CTX-M-1 (13 isolates), bla­_CTX-M-9 (7 isolates) and some ESBL- producing E coli isolates contained two genes bla_TEM+CTX-M-1 (17 isolates) and bla_TEM+CTX-M-9 (10 isolates); (3) ESBL- producing E. coli isolated from fish were mainly identified in group A (27 isolates) and group B1 (26 isolates). Of these isolates, 3 in group B2 and 6 in group D contained virulence factor.