The Flora of Namibia is dominated by the families Poaceae, Asteraceae and Fabaceae. Here, an account of the Apocynaceae, the sixth largest family in Namibia, is presented. A total of 153 species belonging to 46 genera are recorded as occurring naturally for the country and 19 of these species are endemic to Namibia, with two endemic genera. More than half of these 153 species belong to the tribe Ceropegieae, with the highly succulent group, the stapeliads, represented by 58 species. It is shown that the family is most diverse in the extreme south of the country, in the Rosh Pinah and in the Karasburg districts. The distribution of each species is mapped and, for many genera, one species is illustrated with line drawings. Lectotypes are selected for several species. Keywords: Apocynaceae, Apocynoideae, Asclepiadoideae, endemics, largest families, Namibian Flora, Periplocoideae, Rauvolfioideae, Secamonoideae.