To evaluate the bcl-2 protein expression in non small cell lung carcinomas (NSCLC) as an index of apoptosis of these tumors, in fine needle aspiration biopsies (FNABs) of the lung, we studied thirty-eight cases of NSCLC (25 bronchogenic adenocarcinomas and 13 squamous. carcinomas. Bcl-2 protein was used as the primary antibody (monoclonal, DAKO) by Alkaline-phosphatase method. Very light haematoxylin was performed as the counterstain. The results were compared and confirmed histologically. A cytoplasmatic expression of the bcl-2 protein was found in 72% (18 out of 15) of the bronchogenic adenocarcinomas while 61.54% (8 out of 13) of squamous carcinomas showed bcl-2 expression. For the quantitative analysis of our results, we used the t-test and the difference between those two histologic types was regarded as statistically significant with p < 0.001.