The species of Gramineae (Poaceae) that have been recorded in a delimited area of central and western Kenya are listed and keys are provided for their identification. The area is bounded by the 1000 m contour except in the southern Rift Valley where the Kenya/Tanzania boundary encorporates lower altitudes. For every species the life form, size, habitat and biogeographic zones in which it occurs is indicated as far as is known. In total 460 species in 124 genera are listed. The keys use the minimum of technical terms and a description of grass morphology is provided.