The effect of ascorbic acid premedication on dexmedetomidine-ketamine anaesthesia was evaluated in five cats in two sets of experiments namely dexmedetomidine-ketamine (control) and ascorbic acid /dexmedetomidine/ketamine (test). The control group involved concurrent intramuscular administration of 10 mg/kg ketamine and 10 µg/kg dexmedetomidine to each cat. Selected anaesthetic indices and vital parameters were recorded at ten minutes' interval for a period of 90 minutes using standard methods. A week later, the test experiment was conducted with the same cats used in the control experiment but the trial was preceded with intramuscular injection of 20 mg/kg ascorbic acid 10 minutes before the concurrent administration of the previously used doses of dexmedetomidine and ketamine. Vitamin C premedication did not produce any significant difference on heart and respiratory rates and rectal temperature of the treated cats. Onset of drug action was not influenced by premedication with vitamin C and was the same in both control and test groups (3.6 ± 1.50 min). The duration of analgesia was also similar for both control (45.6 ± 13.22 min) and test trials (44.4 ± 10.01 min). Ascorbic acid premedication produced a longer duration of anaesthesia (68.2±17.96 min) than the control (59.6 ± 21.51 min). It also produced a significantly (P < 0.05) shorter time to stand (2.2 ± 2.49 min) than the control (4.8 ± 5.34 min). It was concluded that vitamin C intramuscular administration at a dosage of 20mg/kg prior to dexmedetomidine-ketamine anesthesia in cats produced a longer duration of anaesthesia but hastened the time to stand from sternal recumbency.