Twenty traumatized patients suffering from burns, fractures and bruises were given either 0.5 mg/kg or 1.0 mg/kg ketamine intramuscularly for analgesia. Within 10 min effective analgesia was present in both groups. In the 1 mg/kg group analgesia was more intense, and of longer duration. The higher dose of ketamine led to an impairment in the level of consciousness. Some of the patients of this group were markedly desorientated. The highest plasma levels of ketamine were 147 ng/ml (median) in the 0.5 mg/kg group at 30 min and 474 ng/ml (median) in the 1.0 mg/kg group at 15 min. As to side-effects, 3 patients reported dizziness and 1 patient vomited. Intramuscular applications of 0.5 mg/kg ketamine affords a good but short lasting analgesia with few side-effects.