Isolation and identification of Aeromonas spp. have been performed in 1,610 stools in the period from January 1987 to April 1988. Of 1300 stool specimens taken from the patients with diarrheal syndrome (540 stools of children and 760 stools of adults) Aeromonas spp. were isolated only in 4 patients (0.30%, P less than 0.001). Positive stools were found in 3 adult patients and one child. In 310 examined stools of healthy adult persons Aeromonas spp. were not isolated. A significantly higher incidence of Aeromonas species has been observed in different kind of water. They were isolated in 58.3% in waste water, in 56.2% in river water and in 22.2% in well water. The results have shown that Aeromonas species are not important causative agents of diarrheal syndrome in our country but their importance for public health regarding their high distribution in the nature necessitate their further studies.