The serum ferritin level was detected by radioimmunoassay in 142 patients with hepatocellular carcinoma (HCC). Serum ferritin level was raised (greater than ng/ml) in 38% (54/142) of patients with HCC. There was no difference in serum ferritin levels between stages 1, 2 and 3 HCC. None of the 4 patients with stage 1 HCC had serum ferritin levels above 300 ng/ml. In this small group of patients, measurement of serum ferritin was not a satisfactory indicator of stage 1 HCC. A combination of serum ferritin alpha fetoprotein (AFP) measurements may be useful for a rising suspicion of HCC. We found that a correct diagnosis of HCC was made in 38% (54/142) of patients by measurement of ferritin alone, and in 83.8% (119/142) by measurement of AFP alone, but in 92.3% (131/142) by measurement of a combination of these two markers. Serum ferritin estimation may be helpful in detection of HCC without elevated AFP. Among 12 cases of HCC with serum AFP less than 500 ng/ml, 6 cases (50%) had serum ferritin levels greater than ng/ml. There was no correlation between serum ferritin and AFP, nor between serum ferritin and HBsAg. However, among 12 patients with very high ferritin levels (range 992-3000 ng/ml), 11 (91.7%) had AFP levels of more than 500 ng/ml (mean = 4800 ng/ml, range 500-32000 ng/ml).