Hepatocellular carcinoma (HCC) is one of the most common types of malignancies worldwide. There is little information on the mechanisms involved in the pathogenesis of this disease. Diagnosis of HCC at early stages would be crucial for increasing the survival of patients. Circulating miRNAs have emerged as one of the most attractive tools for an early diagnosis of cancers. Various studies have shown that there is an aberrant expression of miRNAs such as miR-25, miR-375, miR-206, miR-223, miR- 92a, miR-222, miR-1, let- 7f and miR-21 in HCC. Circulating and tissue miRNAs have also key roles in the pathogenesis of HCC by affecting several biologically important pathways such as p53, p21, PTEN, PI3K-AKT, c-Myc and STAT3. In this review, we summarize the current knowledge on the role of miRNAs in diagnosis, prognosis, and treatment of HCC.