Aerosols encountered in the nuclear industry require physical and chemical characterization to determine their transport properties and guarantee their cleanup and control. Such data are also necessary when assessing the consequences of hypothetical severe reactor accidents in which relatively high concentrations of aerosol could be generated containing fission product radionuclides. The concentrations of individual elements and chemical compounds within the airborne particles can be measured, and depth profiling has been used to study aerosol formation mechanisms. The various analytical techniques used to measure the chemical properties of nuclear-based aerosols are high-lighted. The merits and disadvantages of each method are discussed, and guidelines are provided for future developments.