Septorhinoplasty can bring about some serious complications. Clinically, the most frequent complication is septal infection, which may even cause septal perforation and permanent nasal deformity. Previous research reported the incidence of infections after primary septoplasty to be 2.5%. 1,2 For septorhinoplasty, the incidence gets even higher. There are some antibiotic guidelines for sinus surgery, but up to date antibiotic treatment guidelines for the pre-, and post- septorhinoplasty based on literature seems to be lacking. Furthermore, defining the species of the nasal normal flora is still controversial. This study was carried out to figure out the normal flora of nose prospectively. Nasal swab culture was done for the patients who underwent septorhinoplasty in our institute. Based on the result, we aimed to define the boundaries of normal nasal flora and to suggest guidelines for antibiotics in septorhinoplasty.During 2009 to 2011, 140 patients who underwent septorhinoplasty in Korea University Ansan Hospital was enrolled in this study. Preoperative nasal swab was done from the nasal cavity. Among the 140 patients, 70 patients showed positive preoperative microbial culture. The most frequently isolated organism from nasal cavity was Methicillin susceptible Staphylococcus aureus, isolated in 31 patients. Enterobacter aerogenes was found in 16 patients and Methicillin susceptible Staphylococcus epidermidis was found in 8 patients. 73 patients underwent both preoperative and intraoperative nasal swab culture. 30 patients showed positive preoperative culture but negative intraoperative culture. Among them, Methicillin susceptible Staphylococcus aureus and Enterobacter aerogenes were most frequently detected, consistent with the previous culture result. In conclusion, preoperative and intraoperative nasal swab study in septorhinoplasty presented Staphylococcus aureus and Enterobacter aerogenes as the most prevalent intranasal microorganisms. Usage of prophylactic antibiotics targeting both strains, either intravenously or topically, could help reduce the potentially infectious nasal flora and thus prevent postoperative infections after septorhinoplasty.