A new species of shrew tenrec, Microgale macpheei, is described from subfossil deposits in Andrahomana Cave, extreme southeastern Madagascar. This species is distinguished from all named taxa of Microgale by a variety of osteological, dental, and mensural characters. It is presumed to be the sister taxon to the extant species M. brevicaudata, which is not known to occur in southeastern Madagascar. Although the genus contains well over 20 living species, M. macpheei is the first known extinct shrew tenrec in the Quaternary fauna of Madagascar.