Background: More than 50% of patients with type 2 diabetes mellitus (DM) also have hypertension. Moreover, hypertension has been regarded as one paraneoplastic phenomenon of hepatocellular carcinoma (HCC). Our study was designed to determine the relationship between blood pressure and DM in HCC patients. Patients and Methods: A total of 879 HCC patients were included and 151 (17.2%) were diagnosed with DM. Multivariable logistic regression analysis was used to determine the relationship and the results were expressed as adjusted odds ratios (AORs) and their 95% confidence intervals (CIs). Considering the effect of potential confounders, sub-group analysis was performed. We would further study the association of systolic blood pressure (SBP) with fasting glucose, and the association between DM duration/treatment and SBP level. Results: Compared with non-diabetic patients, the diabetic patients had increased levels of SBP (133.7 +/- 18.5 mmHg vs 128.3 +/- 15.2 mmHg, P=0.001) and fasting blood glucose (9.13 +/- 3.04 mmol/L vs 5.18 +/- 1.08 mmol/L, P<0.001), an elder age (58.5 +/- 10.2 years vs 55.3 +/- 11.2 years, P=0.001), a higher percentage of cirrhosis diagnosis (60.9% vs 48.2%, P=0.004), lower percentages of drinking (18.5% vs 30.8%, P=0.002) and smoking (30.5% vs 43.7%, P=0.003), and decreased levels of GGT (median/interquartile-range 88/53-177 U/L vs 117/58-248 U/L, P=0.037), platelet count (121.4 +/- 76.6 x10(9) /L vs 151.2+82.8 x10(9)/L, P<0.001) and hemoglobin (124.3 +/- 25.5 g/L vs 133.6+24.2 g/L, P<0.001). Multivariable analysis showed that, statistically significant differences were found for SBP >= 140 mmHg (AOR=2.101; 95% CI, 1.424-3.100; P<0.001), smoking (AOR=0.637; 95% CI, 0.415-0.979; P=0.040), hemoglobin (AOR=0.990; 95% CI, 0.983-0.998; P=0.010) and platelet count (AOR=0.996; 95% CI, 0.994-0.999; P=0.009). For the relationship between SBP and DM, the positive result was supported by most (10/14) of the subgroup analyses. Conclusion: SBP level was increased in HCC patients with diabetes mellitus.