Open-circuit potential, polarization and electrochemical impedance spectroscopy (EIS) measurements were used to investigate the corrosion behaviour of Ti-6Al-4V alloy in H2SO4 and HCl solutions. The corrosion rate of the alloy was found to increase with increasing acid concentration. The corrosion behaviour of the alloy was compared to that of pure titanium in both acids. The results showed that the alloy is more corrosion resistant than pure titanium in the investigated solutions. The apparent activation energies of the corrosion process for titanium are lower than those of the alloy in the same solutions, which reflects the higher corrosion resistance of the alloy.