A series of europium-substituted Wells-Dawson polyoxotungstates were addressed by P-31 magic angle spinning (MAS) NMR spectroscopy. The electron-nuclear dipolar interaction dominates the (31)p spinning-sideband envelopes. The experimental electron-nuclear dipolar anisotropies were found to be in good agreement with those calculated based on the known crystallographic coordinates and effective magnetic moments and assuming a point-dipole approximation. These electron-nuclear dipolar anisotropies directly report on the anion stoichiometry and on the positional isomerism, indicating that (31)p MAS NMR spectroscopy may be a useful and quick analytical probe of the local environment in Wells-Dawson solids containing localized europium paramagnetic centers.