Experimental studies in vitro and with animals provide scientifi c evidence that the ingestion of n-3 polyunsaturated fatty acids (n3-FA) leads to a reduction in the risk and the growth of colorectal cancer. n3-FA may also increase the effectiveness of chemotherapy treatment and reduce its side effects. However, the epidemiological studies that link colorectal cancer to the ingestion of n-3 FA, show a wide disparity of results, therefore there is not suffi cient evidence to confi rm that n-3 FA ingestion leads to a reduction in the growth of colorectal cancer. The aim of this study is to presents a review of the recent literature that associates cancer of the colon and n-3 FA. It also attempts to contribute to a better understanding of the reasons for the heterogeneity of the results in the epidemiological studies. Despite there being no conclusive evidence in current studies, the results of these studies have led to the making of dietary recommendations aimed at the improving the survival of patients and also of preventing the cancer. These patient dietary recommendations involve increasing the intake of unsaturated fat acids from blue fish 2 or 3 times per week, or concentrated fish oil to a maximum level of 3 g/day.