This study examined whether glycated hemoglobin A1C (HbA1C) and chronic liver diseases are associated with hepatocellular carcinoma (HCC) risk in Type 2 diabetic patients. A retrospective cohort study consisting of 51,705 patients with Type 2 diabetes aged 30 and over enrolled in the National Diabetes Care Management Program before 2004 was used in Cox proportional hazards models. HbA1C was independently associated with HCC incidence, and multivariate-adjusted hazard ratio (HR) of HCC was 1.20 (95% confidence interval, CI: 1.02-1.41) for patients with a level of HbA1c ≥ 9% compared with patients with a level of HbA1c <7% after multivariate adjustment. We observed a significant linear trend in HCC incidence with increasing HbA1c (p for trend = 0.02, HR = 1.07, 95% CI = 1.01-1.12 for every 1% increment in HbA1c). We observed significant HRs of HCC for patients with a level of HbA1c ≥ 9% with alcoholic liver damage, liver cirrhosis, HBV, HCV and any one of chronic liver diseases compared with patients with a level of HbA1c <9% and no counterpart comorbidity in the entire sample (HR = 8.63, 95% CI = 1.41-52.68; HR = 5.02, 95% CI = 3.10-8.12; HR = 2.53, 95% CI = 1.10-5.85; HR = 1.79, 95% CI = 1.01-3.17; and HR = 3.59, 95% CI = 2.56-5.02, respectively). Our results suggest significant joint associations of HbA1c ≥ 9% and chronic liver diseases. Lifestyle or treatment interventions such as maintaining a satisfactory glycemic control and chronic liver diseases may reduce the burden of HCC.