Hepatocellular carcinoma (HCC) is a common malignant disease with poor prognosis. To improve the clinical outcome, early diagnosis of HCC arising from nonviral agents and hepatitis virus is important. Among several etiological factors, mycotoxins defined as carcinogens by the International Agency for Research in Cancer (IARC) might be one of the critical risk factors for nonviral HCC. Aflatoxin B1 is the most well-known carcinogenic mycotoxin for HCC, but the role of the other types of mycotoxin remains unclear. Several studies have reported that a chromatographic separation technique based on high-performance liquid chromatography can successfully detect the concentration of mycotoxins in plasma. Recently, serum level of ochratoxin A (OTA), a widely distributed mycotoxin classified as Group 2B by IARC, was evaluated in HCC patients in Egypt. The results suggested that serum OTA levels might be a good biomarker for HCC. In this article, we review recent studies of OTA, and discuss its possible significance as a biomarker of HCC.