As the number of living donor (LD) and deceased donor (DD) split-liver transplants (SLTs) have increased over the last 5 years, so too has the interest in liver regeneration after such partial-liver transplants. We looked at liver regeneration, as measured by computed tomography (CT) volumetrics, to see if there were significant differences among LDs, right-lobe LD recipients, and SLT recipients. We measured liver volume at 3 months postoperatively by using CT, and we compared the result to the patient's ideal liver volume (ILV), which was calculated using a standard equation. The study group consisted of 70 adult patients who either had donated their right lobe for LD transplants (n โซุโฌ 24) or had undergone a partial-liver transplant (right-lobe LD transplants, n โซุโฌ 24; right-lobe SLTs, n โซุโฌ 11; left-lobe SLTs, n โซุโฌ 11). DD (vs. LDs) were younger (P < 0.01), were heavier (P โซุโฌ 0.06), and had longer ischemic times (P < 0.01). At 3 months postoperatively, LDs had attained 78.6% of their ILV, less than the percentage for right-lobe LD recipients (103.9%; P โซุโฌ 0.0002), right-lobe SLT recipients (113.6%; P โซุโฌ 0.01), and left-lobe SLT recipients (119.7%; P โซุโฌ 0.0006). When liver size at the third postoperative month was compared with the liver size immediately postoperatively, LDs had a 1.85-fold increase. This was smaller than the increase seen in right-lobe LD recipients (2.08-fold), right-lobe SLT recipients (2.17-fold), and left-lobe SLT recipients (2.52fold). In conclusion, liver regeneration, as measured by CT volume, seems to be greatest in SLT recipients. LD recipients seem to have greater liver growth than their donors. The reason for this remains unclear. (Liver