This paper describes the use of CaSO 4: Dy TLD phophor powder and phosphor-embedded Teflon TLD discs in fast neutron dose measurements: The activation of sulphur by the threshold nuclear reaction 32S(n, p) 32P in CaSO 4: Dy was utilized for this purpose. TLD powder and discs were irradiated in a mixed field of neutrons and gamma rays in the APSARA reactor. After a post-irradiation time interval of 2 d, they were given high temperature annealing treatments (to erase all the accumulated TL) and then stored at room temperature. Subsequently, the TL build-up due to 32P betas for different storage time-periods was measured in 60Co gamma equivalent roentgen. For a neutron dose of 6.35×10 4 Rad the accumulated TL signals, after a post-irradiation interval of 20 d, for CaSO 4 : Dy powder and CaSO 4 : Dy Teflon discs were found to be 17.5 R and 8 R equivalent, respectively.