Preliminary results of a prospective study on sialomucin content found either at resection margins of colo-rectal cancer after curative surgery or in endoscopic biopsy specimens of colonic mucosa in thirteen patients selected for the follow up are reported. Though not statistically significant because of the small number of cases enrolled, preliminary data indicate that clinical application of differential mucin staining in colo-rectal neoplasms is potentially useful to predict subgroups of patients at risk for local recurrence as well as metachronous colo-rectal cancers.