This study was carried out to evaluate the anesthetic quality and cardiopulmonary effects of propofol in detomidine premedicated donkeys underwent castration. Seven clinically healthy donkeys were used; each one was used in two trials with one week interval. The donkeys in both trials were sedated by slow i.v injection of 0.04 mg/kg detomidine, 10 minutes later the anesthesia was induced by slow i.v injection of 2 mg/kg propofol. The donkeys were allowed to recover without surgery in the first trial. One week later the same donkeys were used for the second trial where after induction the anesthesia was maintained for 30 minutes by i.v infusion of 0.1 mg/kg/min. propofol. The infusion started 10 minutes post detomidine/propofol induction to accomplish castration. During anesthesia, induction and recovery scores, sleeping and recovery times, respiratory and heart rates and blood gases were assessed. Propofol resulted in rapid induction (20-23 seconds) and smooth recovery with total recumbency period of 29.5 ± 3.29 and 100 ± 10.24 minutes in the first and second trial, respectively. Respiratory rate was significantly reduced with significant increase in PCO₂ in both trials. Thus, i.v injection of 2mg/kg propofol in detomidine pre-medicated donkeys provided rapid, excellent induction and smooth recovery. Maintenance of anesthesia with propofol infusion provided adequate sedation, analgesia and muscle relaxation for castration in donkeys with transient cardiopulmonary changes.