General anesthesia is the administration of certain anesthetics that enable a patient to tolerate surgical conditions. This study was aimed to better explain effects of sevoflurane, and desflurane, inhaled anesthetics, on liver and kidney functions by determining postoperative changes of some biochemical parameters. In this study, 35 patients suited physical status of American Society of Anesthesiologists (ASA) I-II groups were included. Patients with normal renal and hepatic functions were randomly allocated into two groups according to the inhalation agents used. These groups are group of sevoflurane (group S) and group of desflurane (group D). In all groups, general anesthesia was induced with thiopentone and cisatracurium and maintained with 50 % N2O - 50 % oxygen and one of the two volatile agents (desflurane, and sevoflurane). Levels of serum BUN, Urea, Creatinine, AST, ALT were determined in blood samples. Levels of AST in group S and group D increased in post-operation. While there was no significant difference in group D, there was statistically significant difference in group S. The primary effects of volatile anesthetics were on the biochemical parameters of liver postoperatively. Especially, in people with liver disease, it may be considered that desflurane can be a good alternative to sevoflurane in general anesthesia.