The study was aimed to examine the presence of bacterial strains resistant to beta-Iactam and extended-spectrum beta-Iactam antibiotics in animal waste in Vietnam. Forty-five samples of nontreated waste water and biogas effluent from pig farms, and of chicken droppings were collected. PCR analysis of 45 sewage samples showed that 37 samples harbored blaTEM four samples harbored blaSHV. none were detected with blaCTXM. The samples that were positive with blaSHV contained blaTEM. From the PCR-positive samples, 357 bacterial strains were isolated and examined for their resistance to several extended-spectrum beta-Iactam antibiotics as well as for the exhibition of ESBL (extended-spectrum beta-Iactamases). 40,9 percent of the isolates were found resistant to at least one extended-spectrum beta-Iactam antibiotic, of which 53 percent were resistant to two or more antibiotics. Only eight strains expressed ESBL phenotype. Sequencing analysis of PCR products showed that four samples were homologous to blaTEM_1 - a gen coding for classical beta-Iactamases, three were related to blarEM_I04 and one to blaTEM_lb. The two latter encode extended-spectrum beta-lactamases. To our knowledge this is the first report of the presence of bacterial strains containing beta-Iactam resistant genes in livestock waste in Vietnam.