This study examines the incidence and severity of adverse effects of ketamine anaesthesia used for short outpatient procedures in Papua New Guinea. Nine hundred and twenty consecutive ketamine anaesthetics were observed. Eighty‐two adverse events in 77 anaesthetics (8.4% of anaesthetics) were observed. Twelve anaesthetics (1.3%) were complicated by a severe adverse event. These were severe emergence phenomena (nine cases), seizure (one case) and pain necessitating abandonment of the procedure, which occurred twice with the same patient who also suffered laryngospasm during one of these anaesthetics. There were no deaths. Young adult male patients with painful or prolonged procedures had the highest frequency of hallucinatory adverse effects. This study confirms the safety and efficacy of ketamine anaesthesia.