Introduction. Retroperitoneoscopic live donor nephrectomy (RPLDN) was performed because it is considered to be less invasive than open live donor-nephrectomy (OLDN) or transperitoneal laparoscopic live donor nephrectomy. Patients and Methods. Between July 2001 and May 2003, 11.8 consecutive live donor kidney grafts were procured using RPLDN or OLDN. The patients who underwent RPLDN were divided into 2 groups: an initial group 1 (n = 38) and a subsequent group 2 (n = 48). Thirty-two patients who underwent OLDN during the same period were used as controls (group 3). The patients were placed in the lateral position. Three retroperitoneoscopic ports were inserted. The kidneys were retrieved through a 5-cm flank incision just below the 11th rib in group 1. In group 2, a 5-cm Pfarmenstiel incision was used to extract the kidney. Results. The operative time was 307 +/- 88 minutes, 245 +/- 42 minutes, and 21.5 +/- 70 minutes in groups 1, 2, and 3, respectively (group 1 vs group 2 or 3, P <.01). The mean postoperative pentazocine (painkiller) requirements were 12 mg, 4.4 mg, and 22 mg in groups 1, 2, and 3, respectively (group 2 vs group 1. or 3, P <.01). The hospital stay was 6.6 +/- 1.6, 4.9 +/- 0.7, and 7.0 +/- 0.1 days in groups 1, 2, and 3, respectively (group 2 vs group I or 3, P <.01). There were no serious complication, such as massive bleeding or bowel injury. Conclusions. RPLDN may be safer and less invasive than open donor nephrectomy.