Belg. J. Zool., 135 (supplement) : 197-216An extended survey of taxa belonging to two genera of Cricetomyinae (Cricetomys and Saccostomus), one Gerbillinae (Gerbilliscus), eight Murinae (Acomys, Aethomys, Arvicanthis, Lemniscomys, Mus (Nannomys), Mastomys, Grammomys, Stenocephalemys) and one Myoxidae (Graphiurus) was carried out as part of the EU programme “Staplerat” involving Ethiopia, Kenya, Tanzania and Zambia. Here we report the diploid and autosomal fundamental numbers of these rodent taxa. Seventeen of them were unknown, for four we report chromosomal variants and for another 16 new localities where they occur. We discuss their specific status taking into consideration our results together with data from literature and highlight the problems in taxonomy and systematics that are yet to be solved, due do their extended range and the occurrence of species complexes. We highlight cases for which there should be a re-evaluation of specific names that were not included in the last rodent checklist.