OBJECTIVE: To determine the time course of liver hypertrophy after portal vein embolization (PVE). DESIGN: In a cohort study, computed tomography volumetrics were calculated for livers during a 1-year period after PVE. SETTING: Tertiary liver cancer treatment center. PATIENTS: Ten patients who were subjected to PVE and were found subsequently to not be candidates for liver resection. INTERVENTION: Right PVE. MAIN OUTCOME MEASURES: Left and right liver volumes. RESULTS: The left liver continued growing for the entire first year after PVE, while the right liver continued to atrophy. The total volume remained remarkably constant. CONCLUSION: Early PVE during administration of a course of neoadjuvant therapy would be beneficial for enhanced growth of the liver before liver resection.