Bactrodesmiastrum monilioides sp. nov. is described and illustrated from the twig of an unidentified plant collected in Spain. This fungus is characterized by sporodochial conidiomata with moniliform conidiophores, its conidia being solitary, broadly navicular to obovoid, mostly 2-septate, dark brown, with a black band at the septa and basal cell pale brown to brown. Analysis of the ITS region and D1/D2 domains of the LSU of rDNA sequences confirms the placement of this fungus in Bactrodesmiastrum (Sordariomycetes). Because the genus Bactrodesmiastrum was originally characterized by solitary or aggregated conidiophores reduced to a single brown monoblastic conidiogenous cell, an emended description of the genus is provided to accommodate the novel species. A key to species of Bactrodesmiastrum is provided. ; Spanish Ministerio de Economia y Competitividad, Grant CGL 2011–27185. ; http://link.springer.com/journal/11557 ; 2016-06-30 ; hb2015