The luminescence of Cs2NaHoCl6, Cs2NaY0.9Ho0.1Cl6 and Cs2NaGd0.99Ho0.01Cl6 has been investigated down to 10 K under 355 and 457.9 nm laser excitation, and at room temperature under 199.8 and 239 nm excitation. Well-resolved emission is observed from the (5)G(4) level near 25 700 cm(-1) in the low-phonon elpasolite hosts and at 80 K hot bands are observed both to low and to high energy of the (5)G(4) -> I-5(6) transition. The failure to observe emission from other states above 21000 cm(-1) in Cs2NaHoCl6 at room temperature under the high energy excitation lines is attributed to the dominance of nonradiative cross-relaxation processes. (c) 2005 Elsevier B.V. All rights reserved.