The peritoneum is the second most common site of recurrence in patients with colon cancer. Early detection of peritoneal carcinomatosis (PC) by imaging is difficult and adjuvant systemic treatment does not seem to affect peritoneal dissemination in contrast to haematogenous dissemination in the liver or lungs. Of all patients eventually presenting with clinically apparent PC, only a quarter have potentially curable disease. The curative option is cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CR/HIPEC), but the effectiveness depends highly on the extent of disease and is associated with a considerable complication rate. These clinical problems underline the need for effective adjuvant intraperitoneal therapy in high risk colon cancer patients in order to prevent the development of PC with treatment at a subclinical stage.