The electrochemical oxidation of organics in water at boron doped diamonds (BDD) was investigated with the aim to discuss the correlations between the conversion and the instantaneous current efficiency ICE and operative conditions. A simple theoretical model was adopted concerning both the cases of mass transfer control, oxidation reaction control and mixed kinetic regimes. A quite good agreement, between theoretical predictions and experimental data pertaining to the electrochemical oxidation of numerous organics, including some carboxylic acids and aliphatic chlorides, was observed, both for experiments performed in the presence of one or more organics.