to evaluate bacteremias caused during endoscopic examination of the digestive tract.prospective study of randomly selected patients who underwent digestive system endoscopic examination. Emergency endoscopic examinations were excluded.a total of 102 patients were analyzed. Of 44 patients who underwent gastroscopy, 11 (25%) subsequently had positive blood culture, and Staphylococcus spp and Streptococcus spp were isolated. Of 30 patients who underwent colonoscopy, 3 (10%) had positive blood cultures, and Staphylococcus spp were isolated. Of 28 patients who underwent endoscopic retrograde cholangiopancreatography, 11 (39.2%) had positive blood cultures, and Escherichia coli, Morganella morganii, Staphylococcus spp and Streptococcus spp were isolated. No deaths, endocarditis or other septic phenomena were attributed to bacteremia.the incidence of bacteremia ranged from 10% to 39% depending on the type of endoscopy. The microorganisms that were isolated most frequently were Staphylococcus spp and Streptococcus spp. Gram-negative bacilli and enterobacteria were isolated in patients who had undergone endoscopic retrograde cholangiopancreatography.