In this paper, well-dispersed alpha-NaYF4 nanocubes were synthesized with a polyol method. The influence of molar ratio of F-/Y3+/Na+ and type of polyol on the phase and morphology of the as-prepared NaYF4 samples was examined. Formation process of these alpha-NaYF4 nanocubes was traced via time-dependent experiments. Photoluminescence measurements demonstrated the as-prepared nanocubes are good up- and down-conversion luminescent host materials. (C) 2008 Elsevier B.V. All rights reserved.