Tumour growth and expansion are the result of proliferative activity and the capacity to eliminate cells by apoptosis and/or necrosis. The present study was aimed at comparing the apoptosis and proliferation intensity in cells of adenocarcinomas of the large intestine with the expression of metallothionein (MT), the grade of the tumour and the depth to which the tumour infiltrated the intestinal wall. The TUNEL technique and immunocytochemical reactions (expression of caspase-3, Ki-67, MT) were used to detect apoptosis. The results demonstrated augmented levels of all the variables examined, positively correlated with grade of malignancy, G, and with the depth of intestinal wall infiltration by the tumour cells. The testing of apoptosis, proliferation and MT expression may prove useful in the appraisal of the growth and progression of primary adenocarcinomas in the large intestine.