We applied energy-dispersive X-ray fluorescence spectrometry (EDX) and head-space gas chromatography mass spectrometry (HS-GC/MS) for the toxicological screening of stomach contents, notable as employed in a case of pesticide (fenitrothion) ingestion. Elemental analysis by EDX identified high peaks corresponding to phosphorus and sulfur, and HS-GC/ MS analysis identified xylene and ethybenzene in the stomach contents. Subsequent toxicological analysis detected fenitrothion at concentrations of 25.6 and 99.6 mg/g in muscle and stomach contents, respectively. We concluded that the victim ingested fenitrothion. The high peaks corresponding to phosphorus and sulfur by EDX analysis presumably were derived from fenitrothion. Our results indicate that the combination of EDX and HS-GC/MS may serve as a useful tool for screening stomach contents, providing valuable information for forensic diagnosis.