Objective: The Bcl-2 protein increases cell longevity by inhibiting apoptosis (programmed cell death). The aim of this study was to evaluate the expression and possible role of Bcl-2 in skin conditions characterized by the presence of apoptosis. Lichen planus (LP) was chosen as a representative of inflammatory diseases, while basal cell carcinoma (BCC) was the tumor chosen for evaluation. STUDY DESIGN: Routine paraffin sections of formalin-fixed LP and BCCs were labeled with anti-Bcl-2 monoclonal antibody using a biotin-avidin-immunoperoxidase procedure. Numbers of apoptoses in hematoxylin-eosin stained sections were counted in ten high power fields (HPFs) of each section. The results were compared with those in ten age-matched controls. RESULTS: In normal skin samples, Bcl-2 was only expressed by the basal keratinocytes in one of ten (10 %) samples. The mean apoptotic index was 0.5 cell / 10 HPFs. In LP, Bcl-2 was only mildly expressed by the basal keratinocytes in 2 of 20 cases (10 %). Apoptotic cells were present in all the specimens with a mean of 5.35 cells / 10 HPFs. In BCC, Bcl-2 was expressed by tumor cells in 15 of 17 cases (88.24 %). The mean apoptotic index was 4.94 cells / 10 HPFs. CONCLUSIONS: Bcl-2 is not expressed by basal keratinocytes in LP, and probably does not play a role in the epidermal changes (apoptosis) occurring in this disease. Bcl-2 is however consistently expressed by tumor cells in BCC. This finding paired with a relatively high apoptotic index in BCC points to the fact that Bcl-2 plays a role in the pathogenesis of this common tumor.