This article discusses the presence of potentially pathogenic bacteria at the surgical site in patients undergoing endoscopic endonasal surgery. The study collected data from 11 patients who underwent this type of surgery and found that all patients had positive cultures before surgical site preparation. After preparation, 10 patients still had positive cultures, although 8 patients showed a reduction in bacterial burden. Cultures obtained from the skull base after bony exposure was complete were positive in 8 patients, with 3 patients having cultures that grew pathogenic bacteria. However, no patients experienced post-operative infections. The study aims to identify optimal surgical site preparation techniques and determine the source of post-operative infections. [Extracted from the article]