The energy transfer phenomena in GdTaO/sub 4/ activated with Tb/sup 3 +/ have been investigated. It is shown that the ratio of the /sup 5/D/sub 3/ and /sup 5/D/sub 4/ emission intensities of Tb/sup 3 +/ depends strongly on the excitation wavelength. The Tb/sup 3 +/ /sup 5/D/sub 3/ level is populated by direct excitation into the Tb/sup 3 +/ 4f/sup 8/ levels, by energy transfer from the Gd/sup 3 +/ /sup 6/P level or by energy transfer from the intrinsic tantalate group via the Gd/sup 3 +/ /sup 6/P level. The Tb/sup 3 +/ /sup 5/D/sub 4/ level is populated by direct excitation into the 4f/sup 7/5d state, by energy transfer from the Gd/sup 3 +/ /sup 6/I level, or by cross-relaxation from the /sup 5/D/sub 3/ level. Direct relaxation from /sup 5/D/sub 3/ to /sup 5/D/sub 4/ is found to be improbable. The /sup 6/I ..-->.. /sup 6/P relaxation of the excited Gd/sup 3 +/ ion is slow in comparison with the competing energy transfer processes.