Objective: To evaluate the oncological outcome for patients with colorectal liver metastases (CRLM) randomized to associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) or 2-stage hepatectomy (TSH). Background: TSH with portal vein occlusion is an established method for patients with CRLM and a low volume of the future liver remnant (FLR). ALPPS is a less established method. The oncological outcome of these methods has not been previously compared in a randomized controlled trial. Methods: One hundred patients with CRLM and standardized FLR (sFLR) <30% were included and randomized to resection by ALPPS or TSH, with the option of rescue ALPPS in the TSH group, if the criteria for volume increase was not met. The first radiological follow-up was performed approximately 4 weeks postoperatively and then after 4, 8, 12, 18, and 24 months. At all the follow-ups, the remaining/recurrent tumor was noted. After the first follow-up, chemotherapy was administered, if indicated. Results: The resection rate, according to the intention-to-treat principle, was 92% (44 patients) for patients randomized to ALPPS compared with 80% (39 patients) for patients randomized to TSH (P = 0.091), including rescue ALPPS. At the first postoperative follow-up, 37 patients randomized to ALPPS were assessed as tumor free in the liver, and also 28 patients randomized to TSH (P = 0.028). The estimated median survival for patients randomized to ALPPS was 46 months compared with 26 months for patients randomized to TSH (P = 0.028). Conclusions: ALPPS seems to improve survival in patients with CRLM and sFLR <30% compared with TSH.