This study aimed to evaluate clinically the anasthetic overdosage of ketamine in cats.  10 local adult cats from both sexes were used to conduct this study.  High dose of ketamine (150 mg/kg) was administered intramuscularly in all cats. Measurement of heart rate and respiratory rate as well as checking of certain reflexes were performed at regular intervals for 6 hours. Sedation, analgesia and muscle relaxation were evaluated depending on certain scores.  Critical levels or clinical signs of cyanosis were not observed following administration of this high dose of ketamine which was confirmed by the measured values. Deaths of the anesthetized cats were not reported due to ketamine overdosage. High extension of the recovery period was only the main noticed result of the increased dose level of ketamine without any improvement in the anesthetic effect of this drug. Excellent sedation, profound analgesia and moderated muscle relaxation were reported in almost all anesthetized cats. In conclusion, clinical signs of acute toxicity were not reported and severe misjudgments of the bodyweight resulting in high dose of ketamine or even accidental administration increased dose level would not result into fatal outcomes.