The synergistic inhibition behavior of Spondias cytheria and chloride ions on mild steel in H2SO4 solution were studied using the gravimetric and gasometric techniques. From the investigation the results showed that Spondias cytheria and KCl are good corrosion inhibitors. The leaf extract showed maximum inhibition efficiency of 88.52% and 81.42% for gravimetric and gasometric analysis respectively. The leaf extracts + KCl showed maximum inhibition efficiency of 91.49% and 83.76% for gravimetric and gasometric analysis respectively. It was generally observed that the addition of KCl improved the inhibition of the leaf extract. Considering the Ea, Kads, ∆Gads, Qads, the process of corrosion inhibition is attributed to be by physical adsorption. Comparing the R2 values, it could be observed that the data fitted well to Freundlich for the leaf extract and Langmuir for the leaf extract + KCl.