Abstract The liver is one major organ undergoing arachidonic acid synthesis and metabolism; however, the role of arachidonic acid metabolism in hepatocellular carcinoma (HCC) has not been fully elucidated. In this study, the expression of key arachidonic acid metabolism pathway genes in HCC were determined by bioinformatics analysis of publicly available datasets, proteomics analysis of clinical HCC tissues, and immunohistochemical analysis of tissue microarrays (TMAs) of HCC. By comparing the differential expression of hepatic arachidonic acid metabolic genes, we found that the expression of the cytochrome P450 (CYP450) pathway genes, at both mRNA and protein levels, was significantly decreased in HCC tissues. The deregulation of the arachidonic acid metabolism CYP450 pathway is markedly correlated with the pathological features and prognosis of HCC. In addition, we found a significant correlation between the activity of the CYP450 pathway and vascular invasion status in HCC, indicating it would have potential as a predictive factor for early recurrence in HCC patients.