ABSTRACT The present study aimed to perform an epidemiological survey on the prevalence rate of oral lesions diagnosed in a referral center in Brazil and to establish association between the lesions and the age and gender of the affected patients. This analytical observational study analyzed 3521 medical records of anatomopathological exams of the Pathological Anatomy and Cytopathology Laboratory of the Cancer Hospital of the state of Mato Grosso (Brazil), from December 2011 to September 2015. A total of 1550 relevant medical records was detected. Patients aging between 41 and 60 consisted of 42.84% of the sample. Males were more affected than females (60.13%). Inflammatory processess consisted of the most prevalent diagnosis (43.29%), followed by squamous cell carcinoma (6.06%), and periapical granuloma (5.23%). Oral health public policies must give major attention to Brazilian males aged between the fourth and sixth decades of life in order to improve their quality of life.