The alkaloids of Balfourodendron riedelianum were separated from the crude plant extract by a systematic extraction procedure which fractionated the alkaloids according to their basicities and polarities. The structures of two of the alkaloids, balfourodine and balfourolone, have been determined, and it has further been shown that balfourolone is an artifact of the isolation procedure arising from the base-catalyzed ring opening of an O4-methylbalfourodinium salt whose structure is also discussed.