The harvesting of the middle hepatic vein (MHV) with a right hepatectomy for living-donor liver transplantation allows an optimal venous drainage for the recipient but can also have adverse effects for the donor. This study compares morbidity, early liver function, and volume regeneration in 2 groups of donors who underwent right hepatectomy with (MHV؉, n ؍ 21) or without (MHV؊, n ؍ 20) MHV harvesting during 2 successive periods. The operative time was 401 ؎ 60 minutes in the MHV؉ group compared with 392 ؎ 63 minutes in the MHV؊ group, and the transection time was 152 ؎ 53 minutes in the MHV؉ group compared with 131 ؎ 30 minutes in the MHV؊ group (not significant). Blood loss in the MHV؉ group was 773 ؎ 343 mL compared with 613 ؎ 361 mL in the MHV؊ group (not significant). The graft weight and remnant liver volume ratio were similar in the MHV؉ and MHV؊ groups (763 ؎ 200 gm vs. 832 ؎ 156 gm and 42% ؎ 9.5% vs. 43% ؎ 8.3%, respectively). Postoperative biologic liver function tests showed that prothrombin time (PT) ratio on postoperative days 1 and 3 were significantly lower in the MHV؉ group compared with the MHV؊ group (53% vs. 65% and 63% vs. 72%, respectively, P < .05). There were no differences in postoperative alanine aminotransferase and aspartate aminotransferase peak levels between the MHV؉ and MHV؊ groups (319 ؎ 198 IU /L vs. 310 ؎ 110 IU /L and 317 ؎ 226 IU /L vs. 296 ؎ 125 IU /L, respectively). Bilirubin maximal blood level was similar in the 2 groups (32 ؎ 17 mol/L in the MHV؉ group vs. 43 ؎ 16 mol/L in the MHV؊ group, P < .05). No donor died. The overall morbidity was lower in the MHV؉ group compared with the MHV؊ group (36% vs. 55%; P > .05, not significant). The donor's remnant liver volume regeneration, evaluated by computed tomography (CT) volumetric study on day 7, was similar in the 2 groups (97% ؎ 29% in the MHV؉ group and 103% ؎ 39% in the MHV؊ group, P > .05). The results of this comparative study show that right hepatectomy with the MHV neither affects morbidity nor impairs early liver function and regeneration in donors. (Liver Transpl