A model is presented for the variation in reactant concentrations during the electrochemical reduction of 2-ethylpicolinate on a lead cathod in sulphuric acid solutions under galvanostatic conditions. The electrolyses were performed in a laboratory filter-press reactor. Successive or parallel electrochemical reactions coupled with chemical reactions are taken into account, according to a reaction scheme in agreement with the experimental results. Analytical expressions are used to describe the progress of the various reactions, taking into account both chemical and electrochemical kinetics and transfer properties. All reactions are assumed to be first or pseudo-first order. The variations in charge-transfer rate constants are considered as functions of reactant conversion. The effects of acidity, current efficiency, initial concentration of 2-ethylpicolinate and temperature are presented. The model aims at estimating the yield of electrolysis products under the experimental conditions necessary for obtaining 2-hydroxymethylpyridine in optimum quantities.