Abstract <p>The article considers the features of the local plasma electrolytic treatment by the jet feed of an electrolyte onto the side surface of a rotating cylinder made of low-carbon steel. The influence of hydrodynamic parameters of the treatment and voltage on the electro- and thermos-physical characteristics of the process was studied. The optimum values of the electrolyte flow rate, the nozzle diameter, and the distance between the sprayer and the treated surface were established that meet the developed conditions for the efficiency of the local plasma electrolytic treatment. Volt-ampere and volt-temperature characteristics of the process that have common patterns with the treatment by the immersion method when the operating voltage range is shifted towards higher values were obtained. A technique for determining the heat flux into a metal sample during the local treatment with an electrolyte jet was developed based on temperature measurements performed outside the heated area, using which the features of the heat exchange in the electrolyte–vapor–gas layer–rotating cylinder-electrode system were studied.</p>