Abstract: The corrosion rate for mild steel in 2.5 M H2SO4 at 30°C for different flow velocities was determined. Electrochemical techniques such as Tafel polarization and electrochemical impedance spectroscopy (EIS) were carried out to study the effects of flow velocity on corrosion rate of mild steel. The turbulent conditions experiments were simulated using rotating cylinder electrode (RCE). Results obtained from Tafel polarization and EIS were in good agreement. The study revealed that the mild steel corrosion rate decreased with increases in flow velocity due to improvement of the passivation by an increase of the oxygen supply. Corrosion potentials were shafted toward the cathodic values and the magnitude of the impedance was rose with flow velocities.