Spirulina is an edible blue-green microalga that is rich in numerous bioactive compounds especially proteins. Protein deficiency is associated with various disease conditions in human, including cancer. The present study was carried out to evaluate the effect of the marine microalga “spirulina" on protein deficiency signs in hepatocellular carcinoma-bearing mice. Hepatocarcinoma was induced by a single injection of diethylnitrosamine (100mg/kg, intraperitoneally) followed by 22 weekly injections of carbon-tetrachloride (0.5 mg/kg, i.p). Spirulina (250 and 500 mg/kg bw) was given orally, from week 25 to 28, after the establishment of hepatocellular carcinoma. The results showed that HCC-bearing animals several clinical signs of protein deficiency including weakness and skeletal muscle loss, decreased body weight, hair thinnening and loss, in addition to abdominal edema. On the other hand, spirulina-treated animals recovered the signs of HCC-associated protein deficiency. In conclusion, spirulina proved to be an adequate protein source to ameliorate the protein deficiency-related alterations in HCC-bearing animals.