The steady state voltammetry of styrene at Au microdisc electrodes has been investigated in toluene + DMF mixtures as a function of the solvent composition, electrolyte and substrate concentrations and the data compared with that for ferrocene. The experimental data for styrene reveal changes in wave shape and small shifts in half-wave potential not shown by equivalent experiments with ferrocene, and the interpretation of these differences is discussed. The results confirm that the voltammetric response for styrene is a reliable basis for electroanalytical determinations in these media.