Background: The medical management of low-grade squamous intraepithelial lesions (LSIL) is variable, thus a biomarker could assist with the clinical conduct. Type 2 transglutaminase (TG2) has been proposed as a cellular-interfering factor in HPV infection and carcinogenesis. Therefore, this study has the objective of evaluating TG2 expression in LSIL and highgrade squamous intraepithelial lesions (HSIL) and of relating it to the different HPV viral types. Methods: This study included 146 patients with suspected LSIL or HSIL detected in routine conventional Papanicolaou tests. The presence of HPV DNA and viral typing was defined by the polymerase chain reaction method (PCR). TG2 Immunohistochemistry (IHC) was conducted according to the manufacturer's instructions; IHC was carried out in an Autosteiner-Link 48 Dako equipment. IHC quantitation was performed by relative expression and by using the software Image J. Qualitative variables, such as frequencies and proportions, were compared by using the χ2 test for independent samples. For comparison of the qualitative to the quantitative data, nonparametric Mann-Whitney test was used.