Objective: The aim of this study is to investigate the therapeutic role of vitamin A in addition to standard antibiotic treatment on healing of experimental acute maxillary sinusitis. Material and methods: Experimental maxillary sinusitis in rabbits was induced by blocking the left noses and direct inoculation of Staphylococcus aureus into the left maxillary sinuse cavities. Right maxillary sinuses were exposed to serum physiologic as the control group. Animals were divided into two groups. Forty-eight hours after the inoculation, Group A received only parenteral ampicilline-sulbactam (50 mg/kg), Group B were treated with same antibiotic regimen and parenteral a dose of 100.000 IU vitamin A in palmitate form. Animals were killed at 10th day and mucosas of each sinuses were examined histopathologically. Inflammation and sinus epithelium integrity were assessed. Groups were compared with using Mann-Whitney U test. Results: All of the infected sinuses displayed various degrees of inflammation but there was no statistically significant difference between the study and control groups. Although epithelium integrity was slightly better in Group B but the difference was not meaningful. Conclusion: The adjuctive therapeutic role of vitamin A in acute sinusitis was found doubtful but this topic is worth to investigate more comprehensively. (C) 2002 Published by Elsevier Science Ireland Ltd.