Among the various analytic methods of gallstones, infrared spectroscopy has gained popu- larity because of its benefits. Authors analysed 109 cases of gallstone by qualitative infrared spectroscopy and compared them with classification by visual inspection. Coincidence rate be- tween visual and infrared spectroscopic classification was 78% in four boardmen of general surgery and 64.9% in six residents. There was no difference between two groups(p>0.05). The stones classified as pure cholesterol stone by infrared spectroscopy were interpreted as all types of cholesterol stone by visual inspection. Sometimes it was difficult to differentiate calci- um bilirubinate stone frorn black pigment stone by both visual and infrared spectroscopic clas- sification, and it was not possible to differentiate calcium palmitate stone from calcium bilirubinate stone by visual inspection. While all stones containing calcium phosphate by infra- red spectroscopy were interpreted as black pigment stone by visual inspection, stones contain- ing calcium carbonate were interpreted as several types of gallstone. In conclusion, gallstone analysis by visual inspection alone is not perfect, so it is necessary to study and educate accurate interpretation of gallstone by visual inspection and other analysing methods of gallstone including infrared spectroscopy.(Korean J Gastroenterol 1994; 26: 850 858)