Purpose:To analyse and identify factors affecting survival of patients with liver metastasis of colorectal cancer treated by percutaneous ablation. Materials and Methods: Patients with colorectal cancer liver metastasis treated by percutaneous ablation in complex oncological centre from 2005 to 2019 were enrolled in the analysis. The endpoints of the study were overall survival since diagnosis, since the diagnosis of liver metastasis and since the first percutaneous ablation of the liver related to size (on postcontrast axial CT scan),number (1,2,3,multiple) and location(subcapsular,near large vessels,other) of liver metastases and subsequent treatment (surgical resection,systemic treatment,transarterial chemoembolisation). Kaplan-Meier,log-rank and mann-whitney test were used for statistical evaluation. Results:156 consecutive patients (61 women,32,6–89,0 years) with 188 liver metastasis (median 1/patient) with a median size 21mm (4–85mm) were initially ablated.Estimated median survival from diagnosis for synchronous metastases was 51.5months, for metachronous 84.5months. Estimated median survival since liver metastasis in metachronous was 52.9months.Estimated survival since the first ablation was 36.6months in metachronous and 34.2months in synchronous metastases, while the metachronous metastasis were significantly greater (22,5 vs 18,0mm, p=0,005) and patients were significantly older (65,2 vs 60,4 years,p=0,03) at ablation time.Liver metastases of 4-15 mm have significantly better survival since diagnosis of metastases and first ablation than metastases over 15 mm (71.4 and 61.5 vs. 51.5 and 28.7months,p=0.02 and <0.001).No significant difference in survival associated with other factors was observed. Conclusion:Based on retrospective analysis of percutaneous ablation of colorectal cancer liver metastases, the most important survival factor was size of the metastasis, with significantly better results in metastasis up to 15 mm.