RESUMEN
OBJECTIVE: to report the experience of investigating the outbreak of acute diarrhoea (AD) at the XII Indigenous Games in Cuiabá, Mato Grosso, Brazil, 2013. METHODS: data were collected from the Advanced Medical Post's service records of the AD cases, which were defined as 'individual Games participant referring episode of diarrhoea and/or vomiting'; AD attack rates, relative frequencies and measures of the central tendency of sociodemographic and clinical variables, sanitary inspections and results of bromatological samples were calculated. RESULTS: 384 (37%) cases met the definition of AD; the epidemic peaks of the outbreak occurred on the 4th and 7th day of the event and the disease attack rate was 33.5%; sanitary inspection showed evidence of food contamination by coagulase-negative Staphylococci, Bacillus cereus and heat resistant coliforms. CONCLUSION: there an outbreak of AD caused by food contamination.