The aim of this study was to identify lymphocytes subpopulations in 55 middle ear effusions and peripheral blood samples from 33 children undergoing myringotomy for otitis media with effusion. CD3+, CD4+, CD8+, CD19+ and NK cell populations were investigated using three-colour monoclonal antibody and flow cytometry to quantitative estimation. CD3+ cells were the predominant cell type in effusions (mean 63.3%). Percentage CD4+, CD8+ cells and CD4+/CD8+ ratio was significantly higher in middle ear effusions than in blood. Lymphocyte subset was compared between 22 pairs of effusions from each patient. Percentage of each cells did not differ significantly. The results of this study indicate local regulation of lymphocyte profile in middle ear effusions and the same stadium of immune response in two ears of the same patient.