The clinical efficacy and safety of preanaesthetics and induction agents were examined and compared on the basis of clinical and serum biochemical indicators in rabbits. Eight apparently healthy rabbits (3.0-3.5kg) of either sex were arbitrarily allocated into two groups: Group DK (diazepam-ketamine) and Group DFK (diazepam-fentanyl- ketamine). Rabbits were received intramuscular diazepam (5mg/kg), fentanyl (0.02 mg/kg) and ketamine (35 mg/kg). Data on clinical parameters (rectal temperature, heart rate and respiratory rate) and reflexes (righting reflex, palpebral reflex and pedal reflex) were evaluated before and at 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 minutes after injection of anaesthetics. Blood samples were aspirated prior to anaesthesia and 30 minutes following induction. Serum Albumin, Globulin, Cholesterol, Triglyceride, Total Protein, High Density Lipoprotein (HDL), Low Density Lipoprotein (LDL), Creatinine, Calcium, Phosphorus, Sodium, Potassium and Chlorine were evaluated through semiautomatic biochemistry analyzer. In this study, no significant changes in rectal temperature were observed in the animals of group DK during anaesthesia. During anaesthetic cascade, heart rates and respiration rates in both the groups were reduced significantly (P< 0.05). In DFK-injected rabbits, the return of righting and palpebral reflexes were delayed. The DFK groups had considerably (P< 0.05) longer surgical anaesthesia than the DK groups. In terms of serum biochemistry, DK-treated rabbits had significantly lower total protein, globulin, creatinine, HDL, sodium, and potassium concentrations (P< 0.05). Total protein, cholesterol, HDL, and potassium levels decreased significantly (P