The rate of bactaeremia following surgical endoscopy of the upper gastrointestinal tract is reported with up to 50% depending on the therapeutic measure performed. In a prospective study we examined 160 patients treated by surgical endoscopy of the upper digestive tract. The rate of bactaeremia showed a significant difference with 12.5% after diagnostic and 28.96% after surgical endoscopy. Our results recommend a single shot antibiotic prophylaxis depending on the endoscopic measure performed and the patient's individual risk.