We report the case of a 71-year-old female patient with previous history of rectal cancer. The primary cancer was resected and three cycles of chemotherapy were completed. Excision of metastatic lesions was also performed from the left liver lobe. Due to the presence of new liver lesions on the right lobe, intra-operative microwave ablation was decided. Three hours post ablation the patient bled massively and angiography revealed extravasation from a peripheral branch of the right hepatic artery. Successful embolization was performed; however, the patient died 5 days later on liver failure. We would like to present the case and discuss the technical options and the key points to help avoiding similar complications in the future.