Occult hepatic metastases (OHM) from colorectal cancer are those not evident to the surgeon at laparotomy. In this retrospective and "deductive" study the Authors evaluated the accuracy of hepatic CT scan and ultrasonography (US) to detect hepatic metastases. The CT and US accuracy rate was 78.4% and 79.8% respectively, and proved to be correlated to the intraoperative dimensions of the lesions. Sensitivity of these examinations, in the light of OHM identification, decreased to 69% and 69.2% respectively. This study shows that hepatic US and CT scan are not sufficient to identify OHM; the attempt to reduce the frequency of OHM by means of intraoperative ultrasonography could allow to obtain a more careful stadiation and prognosis of these neoplasms with possible therapeutic advantages.