Based mainly on the plant material and data assembled by Röösli & Hoffmann over many years, the Madagascan pachypodiums are reassessed. A complete iconography is provided. A total of 15 species and 4 subspecies are recognized, with an additional new taxon still awaiting publication. The Madagascan taxa are placed in a separate, newly described subgenus Nesopodium within the genus Pachypodium and arranged in three sections with five series, based mainly on the infrageneric taxa of Schumann (1895) and Pichon (1949). The arborescent, white flowering species of section Leucopodium are rearranged in three series; ser. Pseudoternata is newly described. In contrast to other classifications, P. meridionale is treated here as a synonym of P. rutenbergianum, whereas P. sofiense is, in agreement with Perrier de la Bâthie (1934), treated as a species that is distinct from P. rutenbergianum, because of conspicuous differences in flowers and fruits. The distinct position of the red flowering species and their corresponding section Porphyropodium is confirmed. The shrubby, yellow flowering taxa of section Gymnopus are arranged in two series; ser. Densiflora is newly described. A total number of five geographically separated subspecies are recognized within the polymorphic and widespread P. rosulatum, all with similar flower and fruit characters, among them the recently described P. makayense. A further subspecies from this complex has just been discovered by Röösli & Hoffman and is still undescribed. P. eburneum and P. inopinatum are excluded from P. rosulatum, where Rowley (1998, 1999, 2001, 2002) placed them, and are now associated with P. densiflorum. A survey of seeds yielded some useful results: (a) the shrubby species form a morphologically quite uniform entity; (b) P. rosulatum ssp. bicolor is considerably different from ssp. rosulatum; (c) P. baronii and P. windsorii are quite outstanding within the Madagascan pachypodiums; (d) P. decaryi is strikingly similar to P. rutenbergianum and must be closely related, whereas (e) P. ambongense is quite different from this group and seems to be much closer to P. lamerei; it is placed in the new series Pseudoternata, and finally (f) there is a cryptic species that resembles P. ambongense in some respects and P. lamerei in others; it is identified as P. menabeum, which was commonly treated as a synonym of P. lamerei, and it can be placed in the new ser. Pseudoternata. The present treatment of the genus leaves the African species, including the type (P. tuberosum Lindl.), implicitly in subgenus Pachypodium (ICBN Art. 22.1 and 22.3), which is not further considered here.