Following several seemingly straightforward but unsuccessful attempts to prepare a sample of O-17-enriched Cs2WO4, we here report a simple, aqueous procedure for synthesis of pure Cs2WO4, if so desired, enriched in O-17. The purpose for the preparation of O-17-enriched Cs2WO4 is to record its solid-state O-17 MAS NMR spectrum, which would allow for a determination of its quadrupole coupling and chemical shift anisotropy (CSA) parameters and thereby for a comparison with the corresponding S-33 and Se-77 parameters in the related compounds M2WS4 and M2WSe4. These compounds are isomorphous and crystallize in the orthorhombic space group Pnma, and Cs2WO4 turns out to be the only alkali metal tungstate with the Puma crystal structure. Therefore, it has been mandatory to use Cs2WO4 and not K2WO4 (space group C2/m) for which CSA data have previously been published, to achieve a reliable comparison with the S-33 and Se-77 data and thus allow assignment of the three different sets of O-17 NMR parameters to the three distinct oxygen sites (O(1,1), O(2), and O(3)) in the Puma crystal structure of Cs2WO4. Because the ambient temperature O-17 MAS NMR spectrum of Cs2WO4 exhibits a dynamically broadened singlet, resorting to low-temperature (-83 degrees C) conditions at 21.15 T was necessary and resulted in a high-resolution O-17 MAS spectrum that allowed both O-17 quadrupole coupling and CSA parameters to be determined. As no quadrupole coupling data were obtained from the earlier investigation on K2WO4, the present results for Cs2WO4 prompted a reinvestigation of the O-17 MAS spectrum for K2WO4, which actually also shows the presence of O-17 quadrupole couplings for all three oxygen sites. These data for Cs2WO4 and K2WO4 are consistent and result in unambiguous assignments of the parameters to the three distinct oxygen sites in their crystal structures.