Ptilophora Kützing (Rhodophyta) is an algal genus containing 16 species that are predominantly temperate and known mostly from deep subtidal habitats. The genus generally has an Indian Ocean distribution, although two species are found in the north-west Pacific, two in the south-west Pacific, and one in the Mediterranean. Observation of type specimens, specimens from type localities and a thorough review of literature on this genus was carried out to create a comprehensive review of Ptilophora and provide further insight into some poorly understood species. A key to the species in this genus and a distribution map are included, as well as a description and photographic plate of each species. The type species Ptilophora spissa (Suhr) Kützing, only collected once in history, is placed in synonymy with P. diversifolia (Suhr) Papenfuss, having been found to be an aberrant morphology of the latter species. An epitype is designated for P. diversifolia since the lectotype (a figure) cannot be used for detailed studies. Ptilophora beckeri Holmes is reassessed and confirmed to be an unusual reproductive morphotype of P. pinnatifida J. Agardh. Similarly, Phyllophora aegei Giaccone is reassessed and confirmed to be a synonym of Ptilophora mediterranea (H. Huvé) R.E. Norris. The cystocarpic phase of P. rumpii (Dickinson) R.E. Norris and the male phase of P. pterocladioides Andriamampandry are reported here for the first time, and for P. helenae (Dickinson) R.E. Norris and P. leliaertii Tronchin et De Clerck new data on their distributions are added.