In the present work details are given in the first place for the Malesian Icacinaceae, representing the basis of my forthcoming treatment of the family in ‘Flora Malesiana’ in which full descriptions of the Malesian genera and species will be given. Being connected closely with the Icacinaceae of South and Southeast Asia on the one, and with Australia and the Pacific on the other side, and in part even with those of Africa inch Madagascar, it has been necessary to study the respective materials too, without, however, to perform a complete revision of all Icacinaceae in these parts of the world. This was the less necessary, as R. A. Howard (1940—42) already has revised part of the genera concerned. The elaboration of the family in several local treatments has much contributed to our knowledge of the family for Africa. Of the genera formerly included in Asiatic-Malesian Icacinaceae Leucocorema Ridl. has been transferred to Trichadenia Thwait., Matpania Gagnep. to Bouea Meisn., and Petitastira Ridl. to Dichapetalum Thou.