Extracts of tobacco plants show considerable promise as environmentally acceptable corrosion inhibitors. Use of extracts obtained from stems and twigs, as well as leaves, show significant corrosion inhibition during immersion of aluminum or steel in saline solutions and immersion of steel in strong pickling acids. In several cases, the inhibition is greater than that provided by chromates and is provided over a wide range of extract solution concentrations. When steel was treated in sulfuric acid with tobacco extract to remove mill scale and rust, the steel emerged bright and shiny. When treated in sulfuric acid alone, the steel was blackened and pitted. The tobacco extracts provide corrosion protection from a renewable resource with little or no environmental impact. The use of waste plant material enables an inexpensive source of corrosion inhibitors.