SUMMARYCampylobacterare zoonotic pathogens commonly associated with gastroenteritis. To assess the relevance ofCampylobacterin Vietnam, an economically transitioning country in SE Asia, we conducted a survey of 343 pig and poultry farms in the Mekong delta, a region characterized by mixed species farming with limited biosecurity. The animal-level prevalence ofCampylobacterwas 31·9%, 23·9% and 53·7% for chickens, ducks and pigs, respectively.C. jejuniwas predominant in all three host species, with the highest prevalence in pigs in high-density production areas.Campylobacterisolates demonstrated high levels of antimicrobial resistance (21% and 100% resistance against ciprofloxacin and erythromycin, respectively). Multilocus sequence type genotyping showed a high level of genetic diversity withinC. jejuni, and predictedC. coliinter-species transmission. We suggest that on-going intensification of animal production systems, limited biosecurity, and increased urbanization in Vietnam is likely to result inCampylobacterbecoming an increasingly significant cause of human diarrhoeal infections in coming years.