Introduction: LMP-1 (latent membrane protein 1) is a membrane protein found in EBV and can be identified through immunohistochemistry. Objectives: The aim of this study was to evaluate the prevalence of EBV virus in tonsillar tissue samples correlating with tonsil size, age and gender. Methods: An LMP-1 immunohistochemical study was performed in slides from patients with tonsil hyperplasia. Results: The sample consisted of 120 slides, 66 were from male. The average tonsillar size was 6.0 cm2 (1.5-14.0) and the average age was 6.5 years (2-18). Overall, 72 patients were positive for the virus, the majority being male (51%) and preschoolers (51.4%). For comparative analysis, the sample was divided: group 1 (positive immunohistochemistry) and group 2 (negative immunohistochemistry). The average age was 6.74 years (± 4.14) and 6.19 years (± 3.82) for group 1 and 2, respectively. Group 1 had 37 preschoolers, 23 school-age children and 12 adolescents. Group 2 had 28 preschoolers, 14 school-age children and 6 adolescents (p=0.71). To evaluate the presence of virus, the slides were divided according to area: G (≥6cm²) and P (<6cm²). In G group, 54 slides were positive, while in P group, 18 were positive. Group 1 presented 54 of G group slides and 18 of P group slides, with no statistical difference, but with a tendency to positivity (p=0.09). Conclusion: Most of the sample was positive for the presence of Epstein-Barr virus. There was no difference in the virus presence or absence when correlated with the tonsillar size, age or sex.