The electrochemical and surface properties of aluminium in 0.05 M citric acid solutions of pH 2-8 were studied by means of open circuit potential (OCP), potentiodynamic polarization and potentiostatic current-time transient measurements. The OCP reached a steady-state value very slowly, probably due to the slow rate of detachment of surface complexes into the solution. Aluminium exhibits passive behaviour in citric acid solutions of pH 4-8. Tafel slopes b(c) were characteristic for hydrogen evolution on aluminium covered by an oxide film. The corrosion kinetic parameters E-corr, i(corr) and b(a) suggest that surface processes are involved in the dissolution kinetics, especially in the pH range 3-6. Current-time transient measurements confirm that, in citric acid solutions of pH 3-6, the dissolution is controlled by surface processes, that is, by the rate of detachment of surface complexes, while in solutions of pH 2, 7 and 8 dissolution is under mass-transport control. The addition of fluoride ions to citric acid changes the controlling steps of the dissolution process. Citrate and fluoride ions compete for adsorption sites at the oxide surface, and adsorption of these ions is a competitive and reversible adsorption.