Biofilms are sessile communities of bacteria embedded in self-produced extracellular polysaccharide matrix and are considered to be responsible for bacterial infections in humans. Topical surfactant use on silicone nasal splints may have a preventive effect on biofilm formation. The objective of this study is to investigate the effect of surfactant-containing nasal solutions on biofilm formation over the surface of silicone nasal splints. Forty patients were randomized after septoplasty to receive surfactant-containing saline solution (group 1) or saline without surfactant (group 2). At the postoperative 48th, 72th and 96th hours, pieces of splint samples were taken and prepared for scanning electron microscopic evaluation. Biofilm formation was observed in 3, 6 and 14 of 20 samples in group 1 (surfactant used) and 3, 14 and 20 of 20 samples in group 2 (control) at 48th, 72th and 96th hours, respectively. Biofilm formation incidences of groups at 48th hour were similar (p > 0.05), whereas it was significantly lower at group 1 regarding 72th and 96th hours (p < 0.05). Surfactant-containing nasal solutions have an inhibitory effect on biofilm formation over the surface of silicone nasal splints especially after 48 h. Surfactant-containing nasal solutions may have an important role in nasal septal dressing in the future.