Inhibition of low carbon steel (LCS) corrosion in 3.5% NaCl of Pluchea indica Less. leaves extract (PILLE) has been studied using various investigation techniques such as weight loss and polarization methods. The percentage of inhibition increased as the concentration of the inhibitor increased. The results of corrosion test reveal that the extract behaves as a mixed type corrosion inhibitor. Optimum inhibition is reached from 3 mL gambir extract for immersion time of 216 hours. Fourier transform infrared (FTIR) spectroscopy result of adsorbed film on LCS surface containing PILLE shows that in changes in the functional group frequencies of the organic component of the extract.