Despite increasing application and success of personalized treatment in medical oncology, little progress has been made in personalized surgical cancer therapy. The ARMANI trial presents the first prospective, randomized trial to evaluate effectiveness and safety of molecular-guided resection in patients with colorectal liver metastasis (CRLM). While CRLM might be removed independently of the liver’s segmental borders, retrospective data favor anatomic resections in the subgroup of patients with a mutation in the RAS oncogene. Therefore, the ARMANI trial will test the hypothesis, if an anatomic resection (AR) improves long-term outcome vs. a non-anatomical resection (NAR) in patients undergoing surgery for RAS-mutated CRLM. The trial will be carried out among 27 high-volume centers of hepato-biliary surgery in Germany. A total of 240 patients will be enrolled and randomized in a 1:1 ratio to undergo an AR vs. NAR. The primary endpoint is intrahepatic disease-free survival (iDFS). In addition, the study will provide important data on perioperative outcomes and quality of life for both surgical techniques. Given the trend among liver surgeons to aim for parenchymal-sparing operations to preserve liver parenchyma, a positive trial will be practice changing and present the first piece of high-level evidence on benefits of personalized surgical therapy guided by the tumor’s mutational profile in patients with CRLM.