The electrode reaction of the Cd2+ complex with acetylacetone (Acac) was studied on mercury electrodes in the absence and in the presence of n-pentanol and n-octanol. In the inhibitor free solution and under conditions where Cd(Acac), complex predominated, the standard rate constant of the cadmium reaction was found to be 6.2 x 10(-2) cm s(-1). In the presence of inhibitors, it was determined from cathodic and anodic reaction orders with respect to Acac, that the Cd(I)(Acac) species reacted directly with the electrode. In the presence of n-pentanol and n-octanol adsorbed on electrodes, the electrode reaction of the Cd-aq(2+) \ Cd(Hg) system with hydrated Cd2+ ions proceeds more than one order of magnitude slower than the reaction of Cd-acetylacetone complexes. The ionophoretic effect of Acac is postulated to he due to the interaction of the reactant with the adsorbed surface layer.