BACKGROUND: Endoscopic mucosal resection has become a popular alternative for the treatment of early-stage neoplasia of the gastrointestinal tract. However, there are still no data on the frequency of bacteremia associated with this form of treatment. METHODS: We conducted a prospective study of 21 men and 17 women undergoing endoscopic mucosal resection with a cap-fitted panendoscope for upper gastrointestinal lesions. Blood cultures were performed before, 10 minutes after, and 4 hours after the procedure for both aerobic and anaerobic bacteria. RESULTS : Blood culture at baseline was negative in all the patients. Two of 38 patients (5.3 %) had positive blood culture at 10 minutes after the procedure. The isolated microorganisms were Streptococcus salivarius and Corynebacterium species. All patients had negative blood cultures 4 hours later. None of these 38 patients had any symptoms or signs associated with infection. CONCLUSIONS: Bacteremia associated with endoscopic mucosal resection is infrequent and transient