In the last year, a number of studies have reported the expression of bcl-2 in colorectal adenocarcinomas. However, the influence of bcl-2 expression on response to chemotherapy and outcome in patients with advanced colorectal adenocarcinoma has not been reported. We analysed bcl-2 expression in 231 colorectal tumours from patients that were treated by surgery alone or with 5-fluorouracil-based chemotherapy. Of 231 tumours, 149 (64.5%) overexpressed bcl-2. Bcl-2 expression was associated with low plasma CEA levels (P=0.013) and inversely associated with poor differentiation (P=0.049). However, bcl-2 expression did not significantly influence failure-free or overall survival in surgically treated patients. In the group of patients receiving 5-fluorouracil-based chemotherapy bcl-2 expression did not influence response to chemotherapy; nor did it effect failure-free or overall survival.