The aim of present study was to assess preoperative/postoperative serum gastrin level variations and their prognostic value in patients with colo-rectal cancer. Levels have been evaluated in 66 subjects undergoing colo-rectal cancer surgery, with curative intent, from may 1990 to february 1994. Preoperative gastrin analysis was performed on peripheral blood samples in starred patient just prior surgery. Postoperative gastrin assessment was performed 7 day after surgery in starred patients as well. Follow-up ranged from 5 to 8 years. No association between preoperative gastrin levels and tumor site, stage or grading was observed. No significant variation of preoperative gastrin levels (p > 0.05) was ascertained postoperatively neither in the whole patient series nor after correction for tumor stage. Postoperative levels were therefore not affected by surgical removal of cancer. Neither preoperative nor postoperative serum gastrin levels influenced significantly the 5-year survival. In our experience, with the limitation of a small series assessment, serum gastrin level do not seem to have any prognostic value in colo-rectal cancer.