Objectives: Major liver resection is an effective treatment option for patients with liver malignancy. The future liver remnant (FLR) volume and complications after portal vein embolization (PVE) were compared between the ipsilateral right portal vein (PTPE) and trans-ileocolic (TIPE) approaches. Methods: A total of 42 patients (TIPE, n = 22; PTPE, n = 20) underwent right lobectomy after PVE. Computed tomography (CT) and hepatobiliary scintigraphy were repeated before and after PVE. The blood examination findings and the FLR values (FLRCT: calculated from CT, %FLRCT: FLRCT ratio, %FLRSPECT: FLR ratio using single-photon-emission CT, FLRCT/BS: FLRCT to body surface ratio) were compared between two approach sites. The complications and mortality were also analyzed after PVE and major right hepatectomy. Results: There were no significant differences in the patient characteristics, blood examination findings or FLR values between two groups. Adequate liver regeneration was observed without significant differences between PTPE and TIPE (increased ratio of FLRCT: 8.7% vs 19.2%, p = 0.15 [25–75 percentile: 17.1–60.4], %FLRCT: 11.2% vs 8.3%, p = 0.25 [6.3–13.3], %FLRSPECT: 15.4% vs 19.2%, p = 0.09 [16.0–22.4], FLRCT/BS: 33.6% vs 47.1%, p = 0.19 [17.2–60.4], respectively), but TIPE required a significantly longer procedure time than PTPE (181.4 min vs 108.7 min, p < 0.01 [103.3–193.5]). However, one patient was converted to TIPE due to bleeding during PTPE. After right lobectomy, portal vein stenosis or thrombosis was noted in 3 patients (two with TIPE [9.1%] and one with PTPE [5%]) and 3 TIPE patients died within 90 days (13.6%) after right hepatectomy. Conclusions: FLR volume significantly increased after PVE, regardless of the approach sites; however, PTPE is a useful technique with a shorter procedure time.