In view of conflicting results on the fading characteristics of lithium fluoride, a careful reinvestigation has been made on possible fading of the commonly used phosphor, lithium fluoride TLD-100. Measurements over a twelve week period on freshly irradiated powder from a new batch, and also on some old powder, indicate fading of 5 ± 3%, most of which may be due to changes in sensitivity after annealing. Recommendations are made for the proper use of the phosphor in radiation dosimetry applications.