Surgical site marking has been recommended to prevent wrong site surgery (WSS). According to the Universal Protocol promulgated by the Joint Commission on Accreditation of Healthcare Organizations (JCAHO), the mark must be made using an indelible marker that is sufficiently permanent to remain visible after completion of the skin preparation. However, in clinical practice, one skin marker always is non-sterile and used on several patients. Therefore, in theory, there is a risk of contamination of the surgical site from a surgical marker. We hypothesize that the surgical site marking used by the marker which is non-sterile and reused on multiple patients, may affect the surgical preparation and potentially contaminate the surgical field. After a review of the available evidences, we conclude that surgical site marking does not affect the sterility of the surgical field. Surgeons should be more confident in confirming preoperative marking as an effective component in preventing WSS.