Microlepia ravenii S.-J. Moore (Dennstaedtiaceae, Pteridophyta), a new species from northern Vietnam, is described and illustrated. It is morphologically similar to M. marginata and M. hookeriana but differs in having cuneate and not auriculate bases of lower pinnae, cartilaginous and alternatively crenate and denticulate margins of pinnae, and a glabrous undersurface of pinnae.