Air pollution assessment was carried out using chlorophyll concentration reduction criterion of some higher plants leaves such as (Masquerade tree) Polyathia longifolia (Sonn.) Thwaites, (Mango) Mangifera indica Linn. (Guava) Psidium guajava Linn. and (Indian Almond) Terminalia catappa Linn. as the bio-indicator species. The study was carried out at three (3) different locations namely polluted area (Ring Road, Benin City), slightly polluted area (Ekosodin Gate) and unpolluted area (Professor’s Staff Quarters) inside University of Benin, Ugbowo Campus, Benin City, Edo State, Nigeria.