Serum alpha fetoprotein (AFP) is the most widely used tumor marker in detecting patients with hepatocellular carcinoma (HCC). However, it has been indicated that HCCR-1 (human cervical cancer oncogene 1) might be supplementary to AFP in the detection. We conducted a prospective study in 120 normal and 524 liver disease patients to evaluate the significance of simultaneous measurement of 2 tumor markers (AFP and HCCR-1) in the diagnosis of HCC through the cohort study in Korea and China. We also performed immunohistochemical studies using 25 normal subjects (N), 32 liver cirrhosis (LC) and 116 HCC tissues. The sensitivities of AFP (20 ng/mL) and HCCR-1 (10 ng/mL) in HCC were 55.8% (164/294) and 44.2% (130/294), respectively. When AFP was combined with HCCR-1, sensitivities increased to 4.2% (N), 12.7% (chronic hepatitis; CH), 50.0% (LC), and 77.2% (HCC), respectively. Although there was no significant difference in the diagnostic rate for HCC between AFP and HCCR-1, many cases for AFP-negative HCC were positive for HCCR-1 and vice versa. Moreover, the combined use of AFP and HCCR-1 improved the diagnostic rate to 70.8% in small HCC (< 2 cm) and 81.6% in large HCC (≥ 2 cm), respectively. AFP and HCCR-1 are independent markers. Our result suggests that the HCCR-1 could be an useful biomarker for HCC while the diagnostic rate could be significantly improved in the combined use of HCCR-1 and AFP.