Head space capillary gas chromatography was used to detect alpha chloralose and its potent metabolite, trichloroethanol in clinical and forensic cases. Although alpha chloralose was identified in blood and urine in all cases, trichloroethanol was never detected. In a fatal case the alpha chloralose concentration in blood was 151.3 mg/l. It was concluded that trichloroethanol is not a metabolite of alpha chloralose.