The methanol extract of waxy brown rice fermented with Agrocybe cylindracea was prepared. The extract was then freeze dried and fed to rats at the level of 0.5, 1.0, 2.0 g/kg body weight for 14 days, followed by the treatment with carbon tetrachloride for three consecutive days to induce hepatotoxicity. After sacrificing the rats, the enzyme activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and r-glutamyl transpeptidase (r-GTP) in serum was determined. Biochemical analysis on serum for albumin, total protein, triglyceride, and total as well as HDL-cholesterol were carried out along with a histopathological study of liver tissues. Based on these data, we suggest that the waxy brown rice cultured with A. cylindracea may exert hepatoprotective activity against hepatotoxicity caused by chemicals such as carbon tetrachloride.