Abstract: Inhibition of corrosion on AISI 4137 steel in H2SO4 using Cascabela thevetia and Jatropha curcas leaves as inhibitor was studied using gravimetric and gasometric analysis. It was found that the leaves extract of both plants act as a good corrosion inhibitor for AISI 4137 steel in all concentrations of the extract ranging from 0.3 - 1.5 g/l and the inhibitive efficiency increases with increasing concentration of inhibitor. Cascabela thevetia has better surface coverage than J...