Purpose: To determine the effect of aspirin on hepatocellular carcinoma (HCC) recurrence and survival after thermal ablation. Methods: A retrospective analysis was performed to evaluate the efficacy and safety of aspirin in combination with thermal ablation. The clinical data were collected for the enrolled patients. Progression-free survival (PFS), overall survival (OS), and adverse events were analyzed. Results: A total of 174 patients with HCC were enrolled. The median PFS was 11.1 (95% confidence interval [CI]: 8.1-14.0) months for patients who took aspirin and 8.6 (95% CI: 5.5-11.8) months for patients who did not take aspirin. The median OS of patients in the aspirin group was 76.7 (95% CI: 58.1-95.3) months and that in the non-aspirin group was 53.5 (95% CI: 42.7-64.3) months. In patients with non-viral HCC, OS was significantly better for the aspirin group (P = 0.03) after ablation. The PFS of patients who underwent ablation alone in the aspirin group was obviously superior to that of patients in the non-aspirin group (P = 0.002). Stratified Cox regression analysis demonstrated that aspirin use after ablation might be a protective factor in specific HCC patient subgroups. The incidence of major adverse events did not significantly differ between the two groups. Conclusion: Low-dose aspirin use was associated with better OS in patients with non-viral HCC after thermal ablation. In patients who received thermal ablation alone, the administration of low-dose aspirin could improve PFS. Aspirin use might be a protective factor in some patients after ablation.