Steel surfaces of machines undergo corrosion protection most commonly by means of electrodeposited Zn, Cd, Ni, Cr etc. with chemical or electrochemical surface pretreatment for deposition. To preserve the surface geometry steel wire and strips undergo cathodic electrocleaning in an alkaline bath and cathodic etching or pickling in acid solutions. A major obstacle to progression in our knowledge of hydrogen absorption (HA) by metals in the above processes was a lack of techniques for determining the hydrogen distribution in steel, resulting from electrochemical processes at the steel surface. Determination of hydrogen absorbed in the processes of corrosion, cathodic etching and electroplating of metal coating was carried out by means of anodic dissolution of steel. This technique was specially adapted to determine the distribution of electrochemically absorbed hydrogen in steel. For gathering information on the behaviour of hydrogen inside the metal and the deterioration of its stress-related properties, the method of anodic dissolution of steel has no equal. By applying the anodic dissolution technique we were the first to establish the concentration profile of hydrogen in metals (steels, titanium alloys). All the hydrogen absorbed by the cathodically treated metal was found to be distributed in a thin surface layer (δ<0.1 mm for carbon steels), and this layer is responsible for changes in the plasticity and fatigue of steel under static or dynamic loading. The same characteristic is found in the hydrogen distribution in substrate metal (steel) as a result of electrodeposition processes. Peculiarities of the absorbed hydrogen distribution in steel under cathodic polarisation is the aim of the present paper. Examples of experimental data for steel corrosion, Zn and Cd electrodeposition are presented.