The association between aspirin and hepatocellular carcinoma (HCC) has been reported to prevent carcinogenesis caused by hepatitis B or C virus infection. The objective of this study was to investigate the prognostic impact of aspirin in patients who underwent liver resection for HCC. Data for 1032 patients who underwent primary resection for HCC between 2000 and 2019 were reviewed. There were 87 patients (8.4%) who took aspirin (aspirin group) and 945 (91.6%) who did not (non-aspirin group). Short-term outcomes, recurrence-free survival (RFS), and overall survival (OS) were compared between two groups in the matched cohort using propensity-score matching. The median patient follow-up was 42.6months (95% confidence interval 3.12-136.8months). There was no significant difference in short-term outcomes, including bleeding events. RFS and OS after liver resection in the aspirin group were significantly better than those in the non-aspirin group in the unmatched cohort [5-year RFS rate: 50.3% vs 31.4%, hazard ratio (HR) 0.55, P = 0.0002; 5-year OS rate: 82.9% vs 70.2%, HR 0.46, P = 0.002]. In the matched cohort, RFS and OS after liver resection in the aspirin group were also significantly better than those in the non-aspirin group (5-year RFS rate: 50.3% vs 32.0%, HR 0.60, P = 0.003; 5-year OS rate: 82.9% vs 74.6%, HR 0.56, P = 0.03). Use of aspirin was associated with better prognosis for patients who underwent primary resection for HCC.