Ex-situ grazing angle X-ray diffraction and direct reflectance FTIR spectroscopy were used to characterise the composition of the passive layers formed during anodic oxidation of cadmium in alkaline solutions. Measurements were made at different hydroxide concentrations in order to assess the importance of the dissolution/precipitation path with increasing concentrations. The composition of the passive layer was found to depend on the electrolyte cation and on the hydroxide concentration. In LiOH the only product formed was beta-Cd(OH)(2), irrespective of the concentration (0.1-3.7 M) and potential. In NaOH an increasing amount of gamma-Cd(OH)(2) was detected as the concentration increased, from pure beta-Cd(OH)(2) in a 0.1 M solution to mainly gamma-Cd(OH)(2) in a 7 M solution. For KOH, beta-Cd(OH)(2) was primarily formed in the concentration range 0.1-7 M. These data are discussed in the context of surface complexation with emphasis on the effect on crystal growth. Carbon paste electroactive electrodes (CPEE) were used to investigate the reduction of synthesised oxidation products, CdO, beta- and gamma-Cd(OH)(2). The results show that the reduction process is facilitated by the presence of cadmium metal, as revealed from the difference between the first and second reduction scans. These results are interpreted by a re-proportionation path in the presence of cadmium metal.