© 2020 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-FacialIntroduction: As a supplement, beta–glucan has various therapeutic healing effects generated by the immune cells. It has been scientifically approved and proven to be a biological defense modifier. The aim of this study was to investigate the effects of beta–glucan on treatments administered in an acute otitis media model Objectives: This study investigated the effect of beta–glucan on the treatment of acute otitis media in an acute otitis media -induced animal model. Efficacy was evaluated both immunologically and histologically. Methods: The study sample comprised 35 adult rats, randomly separated into 5 groups of 7: Group 1 (control), Group 2 (acute otitis media, no treatment), Group 3 (acute otitis media + antibiotic), Group 4 (acute otitis media + beta–glucan) and Group 5 (acute otitis media + beta–glucan + antibiotic). Analyses were made of the histopathology and immunology examination results in respect of thickening of the tympanic membrane, epithelium damage, inflammation, and sclerosis. In all groups the serum levels of TNF-α, IL-4, IL-6 and IL-1β were evaluated. Results: All serum cytokine levels were significantly lower in the beta–glucan and antibiotic-treated groups compared to the acute otitis media Group. Significant differences in tympanic membrane thickness, inflammation, epithelium damage, and sclerosis values were observed between the acute otitis media + antibiotic and acute otitis media + beta–glucan Groups. According to these parameters, the values in aute otitis media + antibiotic + beta–glucan Group were markedly lower than those of the other groups. There was a significant difference in the acute otitis media + antibiotic + beta–glucan Groups compared to acute otitis media Group (p < 0.001). Conclusions: Both antibiotic and beta–glucan treatment reduced acute otitis media signs of inflammations in an acute otitis media-induced rat model, decreasing histological damage and cytokine levels. Co-administration of antibiotic and beta–glucan led to a significant reduction in tympanic membrane thickness, inflammation, and epithelium damage. Antibiotic + beta–glucan treatment resulted in a greater decrease in tympanic membrane thickness, inflammation, and epithelium damage than in the other groups. From these results, it can be suggested that beta–glucan, in combination with antibiotics may provide an alternative for the treatment of acute otitis media.