OBJECTIVE Treatment strategies for colorectal cancer liver metastasis (CRCLM) such as major hepatectomy and portal vein embolization (PVE) rely on liver regeneration. We aim to investigate the effect of neoadjuvant chemotherapy on liver regeneration occurring after PVE and after major hepatectomy. METHODS CRCLM patients undergoing PVE or major resection were identified retrospectively from our database. Liver regeneration data (expressed as future liver remnant [FLR] and percentage of liver regeneration [%LR]), total liver volume (TLV) and clinical characteristics were collected. RESULTS Between 2003 and 2013, 226 patients were included (85 major resection, 141 PVE). The median chemotherapy cycles was six in both groups. The median time interval between the last chemotherapy and the intervention was 51 days in the PVE group and 79 days in the hepatectomy group. In the PVE group, chemotherapy was not associated with altered liver regeneration (number of cycles [P = 0.435], timing [P = 0.563], or chemotherapy agent [P = 0.116]). Similarly in the major hepatectomy group, preoperative chemotherapy (number of cycles [P = 0.114]; agent [P = 0.061], timing [P = 0.126]) were not significantly associated with differences in liver regeneration (P = 0.592). In both groups, the predicted FLR% was inversely correlated with the %LR (P < 0.001). CONCLUSIONS Chemotherapy does not affect liver regeneration following PVE or major resection. J. Surg. Oncol. 2016;113:449-455. © 2016 Wiley Periodicals, Inc.