Background and aims: Within the framework of the renewed production of the Flore d'Afrique centrale, a manuscript will be prepared on the grasses. Taxonomic novelties, or other information not deemed appropriate in a Flora, will be published in a series of separate papers of which this is the first. The history of research on Central African grasses is briefly sketched. Methods: Standard herbarium techniques have been applied to material from BR, BRLU, GENT, LG and WAG. Some types were studied through the JSTOR Global Plant facility. Key results: Novelties are presented for the genera Acroceras, Axonopus, Paspalum and Urochloa (incl.Brachiaria). Ten new combinations are made. Lectotypes are designated for thirteen names. Eleven names are treated as new synonyms of existing species names, with discussions on the new taxonomic concepts applied. Four species represent new records for the Democratic Republic of the Congo. Keywords: Africa, Burundi, Democratic Republic of the Congo, Flora, Gramineae, nomenclature, Rwanda, taxonomy.