Leaf architecture including venation pattern has been studied in 19 genera and 29 species of the Apocynaceae. The leaves are simple, alternate, opposite or whorled with entire margin and a simple midrib. The major venation pattern conforms to pinnate camptodromous type with festooned brochidodromous secondaries. The qualitative and quantitative features are charted. The leaf size, areole size, number of vein endings entering the areoles and number of vein terminations entering the areoles vary from species to species even within the same species. The highest degree of vein order is observed up to 7°. Isolated tracheids, isolated vein endings, isolated free vein endings and tracheoidal elements are noticed. Bundle sheath cells ensheaths all category of veins.