The aim ot this study was to determine the effects of propofol when added to xylazine-diazepam-kelam ine anaesthetic combination in horse anaesthesia Oy evaluation ol some cardiopulmonary, hematological, biochemical and clinical anaesthetic parameters. In this study a total of six horses were used, and horses were treated two times with two anaesthetic drug combinations at seven days inlerval in random order. In grup I, horses were treated with xylazine-diazepam-ketamine, and in grup II horses were treated with xyiazine-diazepam-ketamine-propofol anaesthetic drug combination. In all horses after last drug injection; anaesthesia induction time, anaesthesia time, and recumbency time to sternal and time to standing were recorded. Quality of induction, anaesthesia and recovery were evaluated. Heart rate, respiratory rate, body temparature; systolic, diastolic, mean blood pressures were evaluated before anaesthesia (baseline) and after induction of anaesthesia up to 30 minutes in 5 minutes intervals. Also for hematological and biochemical analysis venous blood samples were collected before and after induction of anaesthesia at 10, 30, 60, 90 minutes. After induction of anaesthesia cardiopulmonary parameters were decreased below baseline values in first stage of anaesthesia and then they were reached to baseline values in late stage of anaesthesia. It was observed thai when propofol added to xylazine-diazepam-ketamine combination caused transient hypertansion and respiratory depression, and also slightly changed the clinical anaesihetic parameters in good manner, li was concluded that propolol when added to xylazine-diazepam-ketamine anaesthetic combination for anaesthesia of horses produced more safe and adequate anaesthesia without significant changes in vital parameters.