A study of the non quaternary alkaloids of trunk-barks of Polyalthia suaveolens ENGL. and DIELS, Annonaceae, resulted in the isolation of eleven alkaloids, four of which are new compounds. Eight alkaloids are 7-hydroxy or 7-methoxy aporphines; oliverine, oliveridine and polyalthine were found in major amounts. Two oxoaporphines, lysicamine and oxostephanine, are present. Polyveoline, isolated for the first time, is presently under investigation. The phytochemical significance of these alkaloids is discussed.