General anesthesia, either with inhalation or through nonvolatile anesthetics, is known to affect the overall cardiovascular function as well as the microcirculatory hemodynamics. In this study, the effects of desfluran anesthesia on the red blood cell deformability of young and old rats are investigated. 33 male rats were used in the study and the rats were divided into two groups according to their age (young and old) comprising of two subgroups in each. First group was the young control (n=5), the second was the young group treated with desfluran (n=7), the third group was the old control (n=7) and the last group was the old group treated with desfluran (n=7). %6 of desfluran was applied to the rats with inhalation in an adjustable cage for one hour. The elongation indexes of the erythrocytes were measured by a laser diffractometer (Myrenne Rheodyne SSD). Deformability indexes of red blood cells were significantly increased with desfluran in young rats (p=0.042) whereas they were significantly decreased in old rats (p=0.004) with desfluran application compared with their controls. When we compared the young and old control groups, the deformability indexes were significantly higher in old ones (p < 0.001). However, there was no significant difference between the old and the young desfluran applied groups. The volatile anesthetic agent desfluran impairs the deformability of erythrocytes in old rats compared to their controls, whereas it has the opposite effects on young ones. This may be due to the alterations in membrane structure with age. These results reveal that the inhalation of anesthetics like desfluran may cause more serious problems in the elder people during the surgery and may influence their hemodynamic parameters.