Abstract: Mild steel coupons of dimension 4 by 1.5 cm were examined for the purpose of understanding its deterioration behavior in 2 M sulphuric acid solution in the presence of Butyrospermum parkii at a temperature of 60°C. The gasometric technique was used and a number of mild steel coupons were systematically submitted to uninhibited test solutions and those containing extract quantities of 60, 100, 140 cm3. The volume of hydrogen gas evolved data was recorded for 60 min and thereafter analyzed. The results revealed that though extract quantity was increasing, H2 evolution and corrosion rate decreased, while only %I.E increased. The reduction in corrosion rate was observed to follow in order of increasing extract quantity. The phytochemical-metal interaction mechanism was best explained by Freundlich isotherm. The best contact time for the extract phytochemicals to properly adsorb to metal surface at extract quantity of 60 cm3 was 4 min. Furthermore, an expression that explained the correlation between corrosion rate and BP extract quantity was also obtained. The microstructural studies showed that increasing the extract quantity resulted in scanty dispersion of the third phase without any reduction in the pearlite and ferrite phases especially in the 140 cm3 extract which corresponds to a reduction in degradation rate.