There seems to be a consensus in regard to the initial treatment of small hepatocellular carcinomas (HCCs): either percutaneous ablation or liver resection should be selected. Liver resection provides for excellent local control, which is one of the most important factors to be considered in the treatment of HCC. However, percutaneous ablation has the advantage of less invasiveness, which allows for repeated sessions of ablation. However, there has been a longstanding debate on which of the two therapeutic modalities might be superior in individual cases with various tumor-related and liver function factors. Although it is practically difficult to conduct randomized controlled trials (RCTs) to compare these two therapeutic modalities, there have been four RCTs published in English, which we focus on in this review article. We discuss the aforementioned unsolved problem according to the results of these RCTs, in addition to the results of a large-scale cohort study and the recommendations of clinical practice guidelines.