Sammendrag (abstract) BACKGROUND: Radiofrequency ablation (RFA) is one of several minimally invasive treatment options for primary liver cancer and colorectal liver metastasis (CRLM). The purpose of this study was to evaluate overall survival (OS), complications, trends and safety of ablations at Oslo University Hospital, Rikshospitalet (OUS-RH) from 2007 to 2017. METHODS: This retrospective quality study was approved by The Norwegian Data Protection Authority (DPA). Explicit consent had been obtained by all patients in written form. Patient data were collected from registries at the Department of Hepato-Pancreato-Biliary (HPB) Surgery at OUS-RH. Inclusion was procedure-specific with the only inclusion criterion being a completed ablation procedure between 2007 and 2017 at OUS-RH. Kaplan-Meier survival plot was used to calculate OS as well as survival stratified by primary tumour type, lesion size/number and access. Complications were registered according to Clavien-Dindo (CD) score > 2. RESULTS: Out of 343 completed procedures in 297 patients, we found a 1-, 3, and 5-year cumulative survival of 94.8, 73.8 and 48.4 % for CRLM, respectively, and a 1-, 3, and 5-year cumulative survival of 93.6, 67.5 and 46.7 % for HCC. We found a significantly higher OS for patients with solitary lesions < 2 cm. Of all procedures, 334 (97.4 %) were technically successful. A total number of 45 patients had CD-score > 2. CONCLUSION: This single centre study found radiofrequency ablation to be a safe and effective treatment both for HCC and CRLM. There were few complications, and OS and other results were comparable to data found in the literature for hepatic resections.