Scanning electrochemical microscopy (SECM) in ferrocyanide and bromide solutions was used to locate active sites (pitting precursors) on polycrystalline Ti where oxidation of Br- and Fe(CN)(6)(4-) was possible. Analysis of the electroctro-chemically active sites was done by using electron microscopy (SEM), energy dispersive X-ray analysis (EDX), atomic force microscopy (AFM), and in situ confocal laser scanning microscopy (CLSM). In most cases, the active sites were found to be associated with particles (inclusions) which contained mainly Al and Si; however, some other areas not associated with particles were also found to be active. Although the size of the inclusions was normally smaller than 10 mu m, as revealed by SEM and AFM imaging, in some cases larger par-tides were also found. Fitting corrosion tests in bromide solution at potentials above 1.5 V-SCE followed by EDX analysis inside the pits and in situ CLSM observation, confirmed that most oi the localized attack started in the areas where particles had been located.