The biota of Giles County is well known because years of research and teaching activity at the Mountain Lake Biological Station have brought many specialists to the area. No lichenological studies specifically on Giles County, however, have previously been published. The aim of this paper is to report the species of foliose and fruticose lichens collected in the vicinity of Mountain Lake and thereby to add to the already long list of plants known to be present in the total flora there.