Two Bolivian Aspidosperma species were investigated. The seed and stem bark of Aspidosperma macrocarpon Mart, contain six known alkaloids: (—)-vincadifformine, ervinceine, kopsanone, kopsinine, kopsanol in the seed, and kopsanone, kopsinine, kopsanol, 1 8-epikopsanol in the stem bark. The stem bark of Aspidosperma pyrifolium Mart. contains eleven known alkaloids: (— )-vincadifformine, O-demethylpalosine, haplocine, Nformylaspidospermidine, vallesine, demethoxyaspidospermine, palosine, (—)-aspidospermine, aspidospermidine, akuammicine, tubotaiwine, beside the two new bases dehydroxyhaplocidine and 1 0-methoxyaspidospermidine.