Living related liver transplantation offers several advantages in comparison to transplantation of cadaver organs. To achieve maximal donor safety evaluation, selection criteria and complications of the donor operation were retrospectively analyzed in living donors of segmental liver transplants. Seventy-three liver donor candidates were evaluated between October 1991 and June 1994. The median age of 42 mothers and 31 fathers was 31 years (range, 19-50 years). The median volume of the left lateral liver lobe comprised 230 ml (100-350 ml). Twenty-four of 73 (33%) donor candidates were not accepted for living donation. Rejection was due to unsuitability of the donor's liver as a graft (n = 13) or due to an increased risk for living donation (n = 11). Of 35 living donations performed so far, one was a full left hemihepatectomy and 34 were left lateral segmentectomies. The length of the donor operation was, on average, 4.3 hr. No heterologous blood was needed. Postoperative complications included death due to pulmonary embolism (n = 1), seizure due to a previously undiagnosed ependymoma (n = 1), bile duct injury (n = 1), incisional hernia necessitating late revision (n = 2), and duodenal ulcer (n = 2). Long-term follow-up revealed no persistent complications. Using our standardized protocol, 33% of young, presumably healthy donor candidates were rejected for living donation.