The delimitation and subdivision of the tribe Naucleeae s.1. (Rubiaceae) are briefly reviewed and alkaloids isolated from members of the tribe are summarized. Revision of the tribe 5.1. has resulted in the recognition of 21 genera placed in three subtribes. Cephalanthus has been removed to a separate tribe, Cephalantheae, while Mitragyna and Uncarin have been transferred to a new subtribe, Mitragyninae, within the tribe Cinchoneae. The results of alkaloid screening on some 121 small samples, mainly leaves, of herbarium material, representing 18 genera of the Naucleeae s.s., Cephalanthus and Mitragyna, are presented. The majority of genera screened from the subtribes Adininae and Naucleinae were either negative or contained pyridino-indoloquinolizidinones and/or harmane, as indicated by thin layer chromatography. Heteroyohimbine and oxindole alkaloids were rare in genera of the Naucleeae S.S. but were widespread in genera of the Cephalantheae and Mitragyninae. Twenty alkaloids were identified from Cephalanthus species and eighteen alkaloids from Mifragym species. The chemotaxonomic significance of these results is discussed.