The emission and excitation spectra of Ce3+ and Pr3+ doped into the cubic host Cs2NaYF6 have been recorded at room temperature and similar to 10 K using synchrotron radiation. The two 5d(1) T-2g states of Ce3+ have been located from the excitation spectra, whereas the E-g state is placed above the host band gap. Decay measurements of the 5d(1) -> 4f(1) Ce3+ emission, and spectra collected using selective excitation, indicate the occupation of more than one type of site by Ce3+ in this host lattice. By contrast, the location of features in the 4f(1)5d(1) -> 4f(2) emission of Pr3+ is independent of the excitation wavelength. Assignments are presented for some of the 4f(1)5d(1) levels and for the Pr3+-F- charge transfer band. The 5d emission lifetimes for Ce3+ and Pr3+ in the Cs2NaYF6 host are 42 and 29 +/- 1 ns, respectively, and are not temperature-dependent.