The corrosion inhibition of mild steel with Avocado Leaf Extract has been investigated. Avocado (Persia Americana) Leaf Extract was used as corrosion inhibitor known as green inhibitor in this research to prevent the corrosion of mild steel (MS) in acidic media of 0.5 M and 1.0 M of Hydrochloric (HCl). In this work, concentrate of the Avocado leaf extract was added HCl solutions at concentrations of 10ml, 20ml, 30ml, 40ml, 50ml and 60ml. The Avocado leaves were extracted using the soxhlet extractor. Mild steel coupons were prepared, weighed and placed in each environment of 0.5 M and 1 M HCl in numbers of 4 coupons per media. The weight loss measurement was performed by removing one coupon per media at interval of 168 hours and taking the new weight measurements. The experiment was carried out for a period of 672 Hours with readings taken at intervals of 168, 336, 504 and 672 Hours. The corrosion rate and the inhibition efficiency (%IE) were determined. The weight loss of the corrosion rate in 0.5M HCl and 1MHCl has the highest reduction at 60ml (0.0009mm/yr to 0.0004mm/yr) and (0.0035mm/yr to 0.0008mm/yr) with inhibition efficiency of up to 80% and 70% respectively. The corrosion rate (C.R) and the inhibition efficiency (I.E %) represent the weight of the metal surface covered by inhibitor molecules and the values obtained were used to plot all the graphs. An Electrochemical Analyzer equipment was used to carry out the potentiodynamic polarization (Tafel plots) and the Open Circuit Potential and time (OCPT) experiment. The mild steel electrode decreased with increasing concentrations of Avocado Leaf Extract. The reduction obtained indicated the absence of insoluble surface film during the corrosion process and that the inhibitor was first adsorbed on the metal surface and therefore impeded the corrosion process. The results revealed that the extract from avocado leaves (Persia Americana) performed well as a corrosion inhibitor in all the environments used.