The diagnosis of cholera in infants based on clinical grounds is often difficult because other enteropathogens such as rotavirus or enterotoxigenic Escherichia coli (ETEC) can produced a very similar clinical picture. We studied 147 infants admitted consecutively to the Rehydration Unit of Cayetano Heredia Hospital in Lima, Perú, trying to identified those characteristics significantly associated with the isolation of Vibrio cholerae 01 on the admission stool culture. After a univariate comparison of cases and controls were selected those characteristics that showed a significantly different distribution. These were entered in a logistic regression model to analyze their interactions. After this analysis four variables remain significantly associated to cases: no history of fever, dehydration greater than 7%, fecal pH greater than 7 and no glucose in feces. Were developed a diagnostic score with these variables, which had a sensitivity of 77.6% and a specificity of 73.6%. It is important to prospectively validate the utility of this score.