Corrosion of mild steel in hydrochloric and nitric acid solution was studied by weight loss and thermometric methods in presence of ocimum sanctum extract. Fromweight loss data itwas concluded that the inhibition efficiency increases with the increases in the concentration of the extract of stem in HCl and HNO3 solution as compare to extract of leaves of ocimumsanctum. Maximum inhibition efficiency was found (98.67%) in 0.5N HCl acid with 1.2% stem extract, whereas it was (71.62%) in 2N HNO3 acid with same concentration i.e. 1.2%. The corrosion rate was found to decrease with the increases in concentration of extract up to 0.3% to 1.2%. In the case of thermometric method it was concluded that the reaction number decreases with the increases in the concentration of extract while inhibition efficiency increases with increasing concentration of extract of ocimum sanctum in HCl and HNO3 solution.