Objective: Although histological grade and microvascular invasion are known predictors for patient survival and recurrence in hepatocellular carcinoma (HCC), their relationship with various clinical and histomorphological features of HCC remains unclear. Materials and Methods: Medical records were retrieved from 61 patients who were diagnosed with HCC from 2008–2018. Clinical and histomorphological variables that were hypothesized to be associated with histological grade and microvascular invasion were analyzed statistically using the Chi-square test or the Fisher’s exact test as alternatives. Multivariate analysis was performed with logistic regression model. Results: The majority of the patients had well to moderately-differentiated HCC (67.2%) with some of them presenting microvascular invasion (57.4%). Alpha-fetoprotein level (AFP) ≥100 ng/ml (p=0.036), tumor size >7cm (p=0.031) and mitotic index ≥5 per 10 high power field (p=0.009) were significantly correlated with poorly-differentiated HCC. Mitotic Index ≥5 per 10 high power field was an independent factor for poorly differentiated HCC. Meanwhile BCLC stage B and mitotic index were also an independent factor for the presence of microvascular invasion. Conclusion: Larger tumor size and higher mitotic index was significantly correlated and independent factors for poorly differentiated HCC and microvascular invasion. In biopsy specimens for which the microvascular invasion is difficult to assess, histological grade, tumor size and mitotic index may be beneficial to depict the prognosis of patients with HCC. © 2023, Faculty of Medicine Siriraj Hospital. All rights reserved.