Young leaf of Duboisia myoporoides was found to contain valtropine and scopolamine as the major alkaloids. Other alkaloids extracted included tigloyl tropine, valeroidine and hyoscyamine. An alkaloidal mixture of the young stems on subsequent fractionation yielded scopolamine and valtropine as principal alkaloids. Valeroidine and tropine were minor constituents.An ether extract of the old leaf of D. myoporoides gave scopolamine, valtropine, hyoscyamine, butropine, poroidine, valeroidine, acetyl tropine, noratropine, isoporoidine, apohyoscine and tropine. From the old stems, valtropine, scopolamine, atropine tropine, valeroidine, norhyoscine, apohyoscine, noratropine, butropine and hyoscyamine were isolated.