The aim of this study was to investigate the role and function of somatostatin, glucagon and gastrin in 35 colorectal adenocarcinoma and 25 liver metastases. The investigation was carried out at the electron immunocytochemistry level. Our results showed that well-differentiated tissues have the highest somatostatin levels compared to poorly-differentiated tumors while glucagon levels remain high. We also found gastrin immunoreactivity in cell membranes of poorly-differentiated primary adenocarcinoma tissues and in liver metastases. Low somatostatin expression, high glucagon expression and the presence of gastrin were found in tumors of poor grading and therefore poor prognosis.