Abstract: We investigated the effects of algae (Chlorella vulgaris and Enteromorpha sp.) incorporated diets in the prevention of diethyl nitrosamine (DEN: C4H10-N2O) induced hepatocarcinoma in rats. Toxicity was induced by i.p. administration of DEN in multiple doses @ 150 mg kg-1 BW. Rats were divided into 8 experimental Groups and fed either with control diet (synthetic diet without algae) or algae incorporated synthetic diets for a period of 8 weeks. DEN treated rats fed with synthetic diet showed a significant (p<0.05%) reduction in bodyweight, organ weight and relative organ/bodyweight, while Groups fed with algal diets showed gradual recovery from the morphological phenomenon. Likewise, algal diets helped in the process of improvement from liver damage as judged by studying the fluctuation of liver enzymes namely cytochrome P-450, SGPT, G-6-phosphatase and amino-n-demethylase. Serum enzymes, cathepsin B, cathepsin D, ß-D-galactosidases and glucosidases showed significantly (p<0.05%) lower activities in algal diet fed Groups than the synthetic diet fed Group. These results imply or suggest that a combination of Chlorella and Enteromorpha in diets is efficient in limiting the action of DEN during the initiation phase of hepatocarcinogenesis in rats and may help in prevention of liver damage.