Thermoluminescent dosimetry (TLD) was successfully evaluated as an in-core thermal-neu-tron-flux determinant. The LiF crystals enriched with either 6Li or 7Li provided two effective neu-tron-gamma discrimination techniques. The first method used both types of crystals. The 6LiF dosimeters, which have large thermal-neutron cross sections, detected both neutrons and gamma radiation, while the 7LiF dosimeters, possessing negligible thermal-neutron attenuation characteristics, monitored the gamma component only. The dosimeters were inserted into a reactor for a known time interval and read on a commercially available detection system, and the difference in dosimeter exposure yielded a direct measure of neutron flux. The second technique used bare and cadmium-covered 7LiF dosimeters. The bare crystals detected reactor gammas, while those encapsulated in cadmium measured reactor gammas plus capture gammas from the Cd(n, γ ) reaction. The difference in exposures provided the capture-gamma contribution, which was proportional to reactor flux. Experiments using a subcritical and a TRIGA reactor revealed exposure rate to neutron flux sensitivities of 1.4 × 10−7 R/sec per ϕ and 2.6 × 10−8 R/sec per ϕ for the respective techniques. Accurate flux measurements were obtained over a range spanning 102 to 1012 n/(cm2 sec). At higher fluxes, the dosimeters experienced radiation damage and readings became unreliable. The TLD results were compared against BF3 detection, foil activation, and fission chambers to derive an empirical exposure rate to the flux conversion factor.