Among ion‐beam‐based analytical methods, direct observation of nuclear reactions induced by highly energetic (Me V domain) charged particles is dedicated to quantitative determination of volumic distributions of light elements from
Z
= 1 (H) to
Z
= 41 (Ga) in the near surface region of solids. In most cases, discrimination between their isotopes is enabled up to
37
Cl. The incident ions are generally protons, deuterons, helium‐3, or helium‐4 ions. Nuclear reactions induced by heavier ions are rarely used, mostly for hydrogen depth profiling. All these reactions are characterized by the prompt emission of charged particles (protons or helium‐4 ions) and/or γ‐rays. Nuclear reaction analysis (NRA), performed in ion millibeam or microbeam modes, is an efficient complement to charged‐particle‐induced X‐ray emission, Rutherford backscattering spectrometry, and elastic recoil detection methods. Its applications are all intended for either absolute quantification or tracing experiments. They cover a broad panorama from life sciences to cultural heritage artifacts, including metallurgy, Earth sciences, nanotechnology, and material science.