This study is the first 20th century world monograph of the genus Coniophora DC. ex Mérat. Fifteen species and two varieties are placed in synonymy with other Coniophora names and an recognized 60 names are placed in synonymy with other Coniophora names and an additional 61 names are excluded from the genus. Coniophora mollis is described as a new species. Cylindrobasidium corrugun (Burt) Ginns, Gloecosystidiellum steroideum (Rick) Ginns, Bourdotia radians (Rick) Ginns and Basidiodendron fulvum (Mass.) Ginns are proposed as new combinations. Taxonomically a combination of spore, basidial and hyphal features are important in assigning a species. Cultures of the 6 species available for study were quite similar. While microscopic characters were more constant between isolates of a species the gross morphology of some isolates varied to the point of overlapping the features of other Coniophora species. All species are lignicolous, showing a distinct affinity for the wood of coniferous species, cause a brown rot and some are often or exclusively known from domestic habitats (i.e., in buildings, mines etc)