Background: The association between leptin, adiponectin levels and the risk and prognosis of hepatocellular carcinoma has been investigated by a growing number of studies, but the results were controversial. Methods: We performed the meta-analysis to assess the relationships between leptin, adiponectin levels and the risk and prognosis of hepatocellular carcinoma (CRD42020195882). Through June 14, 2020, PubMed, Cochrane Library, Embase databases, Clinicaltrials, and Opengrey was searhed, including references of qualifying articles. Titles, abstracts, and articles were reviewed by at least 2 independent readers. Stata 16.0 was used to calculate statistical data. Results: Thirty studies were included in this meta-analysis and results showed that hepatocellular carcinoma group has significantly higher leptin levels than the cancer-free control group (SMD = 1.83, 95% CI (1.09, 2.58), P = 0.000) , the healthy control group (SMD = 4.32, 95% CI (2.41, 6.24), P = 0.000) and the cirrhosis group (SMD = 1.85, 95% CI (0.70, 3.01), P = 0.002). Hepatocellular carcinoma group has significantly higher adiponectin levels than the the healthy control group (SMD = 1.57, 95% CI (0.37, 2.76), P = 0.010), but no statistical difference compared with the cancer-free control group (SMD = 0.24, 95% CI (-0.35, 0.82), P = 0.430) and the cirrhosis group (SMD = -0.51, 95% CI (-1.30, 0.29), P= 0.213). The leptin rs7799039 polymorphism was associated with an increased the risk of hepatocellular carcinoma (G vs A: OR = 1.28, 95% CI (1.10, 1.48), P = 0.002). There were linear relationships between adiponectin levels and the risk of hepatocellular carcinoma (OR = 1.066, 95% CI (1.03, 1.11), P = 0.001). In addition, the results showed that high/positive expression of adiponectin was significantly related to lower overall survival in hepatocellular carcinoma patients (HR = 1.70, 95% CI (1.22, 2.37), P = 0.002); however, there was no significantly association between the leptin levels and overall survival (HR = 0.92, 95% CI (0.53, 1.59), P = 0.766). Conclusion: The study shows that high leptin levels were associated with a higher risk of hepatocellular carcinoma. Adiponectin levels were proportional to hepatocellular carcinoma risk, and were related to the poor prognosis.