Abstract: INTRODUCTION: Rhinosporidiosis is a chronic infection of the mucous membrane and is caused by Rhinosporidium seeberi, an aquatic mesomycetozoan. The mode of infection is probably transepithelial penetration. The large number of rivers and lakes and the strong presence of riparian populations in the State of Maranhão are strong predisposing factors for rhinosporidiosis. METHODS: A 5-year retrospective study was conducted in a tertiary medical center situated in Maranhão, Northeast Brazil. Twenty-five Maranhense patients diagnosed with rhinosporidiosis were analyzed. RESULTS: Most of the patients were children, adolescents and young adults (age range: 7-24 years, mean age: 14 years). The majority of the participants were male (84%), brown (76%), and students (92%). All lesions involved the entire nasal cavity and presented with a vascular polypoid mass. All patients were treated by surgical excision of the lesions. CONCLUSIONS: Rhinosporidiosis affects younger age groups, especially students from the countryside and the outskirts of urban areas. This study will aid and guide physicians in diagnosing and treating this infection in endemic areas.