Chondroitin sulfate iron colloid (CSIC)-enhanced MRI is a new method for the detection of hepatocellular carcinoma (HCC). After intravenous injection, CSIC is rapidly incorporated into Kupffer cells in the liver. The aim of this study is to investigate the value of CSIC-enhanced MRI in detection of HCC and to compare with conventional MRI and CTAP. HCC was diagnosed by serum AFP, ultrasonograpy, conventional abdominal CT, and liver biopsy. Hepatic MR images were obtained before and one hour after finishing injection of CS1C in 22 patients with HCC. CT during arterial portography (CTAP) was obtained in 9 of 22 patients with HCC. After injection of CSIC, signal intensity of normal hepatic tissue was decreased, whereas signal intensity of tumor was not changed as compared with conventional MRI, and tumor to liver contrast was increased in all patients. CSIC-enhanced MRI revealed a total of 82 HCC lesions, however conventional MRI revealed only 70 HCC lesions. Especially, when the lesion was less than 1 cm, CSIC-enhanced MRI showed ten additional lesions compared with conventional MRI. Comparing with conventional MRI and CSIC-enhanced MRI, CTAP showed four and two more lesions, respectively. Our results suggested that CSIC-enhanced MRI was comparable to CTAP in the detection of HCC, and, compared with conventional MRI, it increased the detection rate of small HCC, especially those less than 1 cm in diameter.