Herbicides are frequently used in agriculture for control of weeds in crops. Quizalofop-ethyl is a postemergence herbicide widely used for control of grassy weeds in crops, intended for human consumption. The general population may be exposed to quizalofop-ethyl via ingestion of food or drinking water. Sometimes it is misused for suicidal poisoning. A systematic analysis of herbicides acting as poison in human body is carried out by forensic toxicologists. Their method involves screening of poison followed by its instrumental assay. Therefore a simple, rapid, sensitive and reliable thin- layer chromatographic method for detection of quizalofop-ethyl is presented. The quizalofop-ethyl contain quinoxaline ring in its structure having –N=C-CH=N --group. These react with Dragendorff`s reagent to give orange-red coloured spot in yellow background. The detection limit was found to be 10 μg per spot (20 μg/cm2). The constituents of viscera (amino acids, peptides, proteins, etc.) do not interfere in the test.