Deep level transient spectroscopy ofp–njunctions, Schottky barriers, or metal‐oxide‐semiconductor (MOS) capacitors is widely used to obtain the concentrations of defects and their profiles in semiconductors. The use of this technique for profiling presents several difficulties, some of which have not been taken into account in the works previously published. The aim of this paper is to describe the exact analysis which should be performed to obtain correct profiles. The analysis is tested on a constant defect profile, induced by electron irradiation inn‐GaAs, in order to illustrate the effect of each correction. It is then applied to defect profiling of a silicon MOS capacitor and on the EL2 defect in annealed GaAs.