A new delimitation and subdivision of the Crypteroniaceae (Myrtales) is given; no less than five genera, Crypteronia, Dactylocladus, Axinandra (all SE. Asia), Alzatea (S. America), and Rhynchocalyx (S. Africa) are included. Traditionally the Crypteroniaceae were considered to be a monotypic family. The family is subdivided into two subfamilies, Crypteronioideae and Alzateoideae, the subfamilies each into two tribes, and some of the genera into sections. Of these taxa descriptions, synonymy, references, and notes on distribution and ecology are given, as well as a key for their identification. Of the species recognized only names, typification, synonyms, and distribution are briefly mentioned. In Crypteronia one new species, C. macrophylla, is described. Argumentation for the present taxonomical treatment is given in a separate article in the next issue (Van Beusekom, 1975).