The isolation of picrinine, strictamine, tetrahydroalstonine and an uncharacterised indole alkaloid is reported from the flowers of Alstonia scholaris. Picrinine, the major alkaloid, bas been found to possess central nervous system depressant action. Alstonia scholaris R. Br. is a large evergreen tree widely cultivated throiighout India. ~tbears compact, umbellately branched, pubescent cymes of greenish-white fragrant flowers (HOOKER, 1882). The bark, leaves and fruits of the plant have been examined and alkaloids, echitamine (HAMILTON etal., 1961), echitamidine (DJERASSI et al., 1962), picrinine (CHATTERJEE et al., 1965), rhazine (CHATTERJEE et al., 1969) and picralinal (RASTOCI et al., 1970) have been isolated and fully characterised. In an investigation designed to yield information on the distribution and relationship of alkaloids in A. scholaris, we studied the occurrence of alkaloids in the flowers. The pharmacological action of the' major alkaloid, picrinine, has also been studied as a part of Our research program.