Partial hepatectomy is a major upper abdominal operation associated with certain stress to the patient. Successful adaptation to such stress is a prerequisite for survival. Donor hepatectomy with maximal safety is a principal concern during living donor liver transplantation. The purpose of the study was to compare the stress response by assessing cytokines and the acute-phase response induced by hepatectomy in patients with a healthy liver and those with a diseased liver. Fourteen patients undergoing partial right hepatectomy were enrolled in this study. Seven of them were donors for living related liver transplantation (group 1, or GI); the other seven were patients with hepatocellular carcinoma due to chronic hepatitis B (Child's class A) (GII). Blood samples for interleukin-6 (IL-6), tumor necrosis factor-alpha (TNFalpha), and C-reactive protein (CRP) assays were collected before the operation, at the beginning and end of the operation, and 24 and 48 hours after the operation. The data were analyzed and compared in the same group using the Friedman test and between groups using the Mann-Whitney U-test. A value of p < 0.05 was regarded as significant. Results showed that resection of the liver in patients with both healthy and disease livers leads to significant increases in IL-6 and CPR but not TNFalpha. Significantly lower levels of IL-6 before and after operation in GI patients compared to those in GII patients suggests that GI patients adapted to surgical stress more easily than did the GII patients.