This preliminary list is as complete a catalogue of the vascular plants of Giles County, Virginia, as could be prepared from two, summers of field work by the authors (in 1956 and 1958 respectively) and from previous collections maintained in the herbarium of the Mountain Lake Biological Station on Salt Pond Mountain. These previous collections were made by several students and teachers of plant taxonomy who have worked in the area since the founding of the Station in 1930. The collections of Dr. H. H. Iltis are among the more important of these. The list is reasonably complete for the grounds and immediate vicinity of the Station and for much of Salt Pond Mountain. It undoubtedly has many omissions for the rest of the county, especially among the more ephemeral spring and late summer bloomers that were not recognizable during the ten weeks in which the Station functions each summer. We hope it will be useful to the students and staff of the Station while serving as the basis and stimulus for a more complete catalogue in the future. A few species not collected from Giles County, but from nearby areas across the county boundaries are included because of their ready accessibility to the Station and because of their probable occurrence in Giles County also.