173 children hospitalized with acute diarrhea are studied retrospectively with the object of finding clinico-analytic parameters suggestive of bacterial etiology. The 88 boys and 85 girls varied in age between 3 months and 10 years (only 20% were under a year). The children were divided into 2 groups: group D (+) were 39 children with positive stool cultures (salmonellas, 64%; campylobacter, 25%, and shigellas, 11%), and group D (-) were 134 children with negative stool cultures, and served as a control group. Various parameters were analyzed in order to define the socio-economic and nutritional status, and psychomotor development. Careful analysis was made of the patients' histories and exploratory findings, with special emphasis on the characteristics of the feces. Using the chi-square statistical analysis, significant differences between the two groups were found in relation to length of hospital stay, which was longer in group D (+) (p less than 0.001), the appearance of blood in stool, more often in group D (+) (p less than 0.05) and in the number of children of group D (+) with band forms greater than 10% (p less than 0.05). In accordance with our findings, the practice of stool cultures should be limited to those patients with acute febrile diarrhea presenting macroscopic blood in stool and leukocytosis with neutrophilia (excepting children under 3 months of age, those in a critical or malnourished state, immunodepressed or in a particular epidemic situation). In this way the number of stool cultures and medical assistance costs would be markedly reduced and a more adequate cost/benefit relation would be obtained.