The aim of this study was to investigate the effect of isoflurane (ISO) and sevoflurane (SEVO) anesthesia on coagulation parameters in dogs. A total of 12 dogs were used in the study in two groups as ISO(n = 6) and SEVO(n = 6), which were brought to the clinic for ovariohysterectomy. Premedication was performed by the intravenous administration of 0.3 mg/kg midazolam, followed by 5 mg/kg intravenous bolus propofol infusion. This was followed by 1.5% ISO administration in the ISO group and 2% sevoflurane administration in the SEVO group for anesthesia maintenance. Before anesthesia, prothrombin time (PT), active partial thromboplastin time (APTT), thrombin time (TT), and fibrinogen (FIB) level were measured at the 0th minute before anesthesia, at the 15th and 30th minutes during anesthesia, and at the 0th minute and the 1st hour after anesthesia. It was observed that the changes in TT, PT, APTT, and FIB level with time were not significant in the ISO and SEVO groups. It was determined that the changes in TT between the measurements in groups at the 30th minute during anesthesia and 0th minute after anesthesia were statistically significant (P less than 0.05)