SummaryIndium 113mis a radioisotope with a half-life of 1.7 hour and a monoenergetic gamma radiation of 393 KeV.It may be prepared by elution of a Sn113generator. Several molecules labeled with Indium may be quickly and easily obtained.The physical and chemical properties of Indium are described along with a study of the isotope generator.The various clinical applications of Indium 113mare discussed and illustrated. Indium stablilized by gelatine may be used for determination of intravascular space, measurement of cardiac output and scintigraphy of the heart and placenta.Indium chelated by DTPA is used in nephrography, renal and cerebral scintigraphy and measurement of glomerular filtration rate. Colloidal Indium is used in hepatic and splenic scintigraphy. Finally, scintigrams of the lungs may be obtained by means of Indium labeled macroaggregates of iron hydroxyde.