Thirty-two isoquinoline alkaloids have been isolated from the trunk bark and leaves of Guatteria sagotiana. With the exception of two benzyltetraisoquinolines, they are aporphinoids. Five of them are new: an aporphine, N-methylelmerrillicine (16); a 7-hydroxyaporphine, nuciferidine (23); a dehydroaporphine, dehydrostephalagine (29); a 7-methyldehydroaporphine, trichoguattine (31); and an alkaloid of the novel azahomoaporphine typ, dragabine (32).