Granzyme B (GrB) is a serine protease synthesized in T lympocytes (CTL), released after T-cell activation resulting from exogenous stimulation. With perforin, GrB discharges apoptotic signals to a target cell and therefore constitutes a marker to identify activated CTL. We aimed to quantify GrB expression by immunohistochemistry staining in 12 tissue fragments of cervical carcinoma, 33 cervical intraepithelial neoplasias treated by LLTEZ and nine cervical pieces without disease. Activated cytotoxic lymphocyte mean values (20 HPF-400x) in both epithelial and stromal pars were 7.11 cells in tissue without neoplasia, 33.45 cells in cervical intraepithelial neoplasia and 139.75 cells in carcinoma samples, with a statistical difference between them. Comparative analysis in the CIN group showed an expressive difference between cases with disease recurrence (19.28 cells) and without recurrence (37.26 cells). Thus, the relation between number of activated CTLs found at the moment of treatment and clinical evolution determined in this study, suggest GrB use as a prognostic marker.