Triple-resonance 1H,19F,13C solid-state CPMAS NMR was used to examine the miscibility of isotactic, syndiotactic, or atactic PMMA with poly(vinylidene fluoride) (I). From the fluorine-to-carbon cross-polarization expts., the av. distance between F and OCH3 carbons in intimately mixed I and PMMA was estd. Exptl. evidence for a specific interaction between I and PMMA segments was presented. The proton-to-fluorine cross-depolarization expts. yielded information on size and compn. of the mixed PMMA/I phase. The fraction of nonmixed PMMA was detd. for these blends, and this fraction was smaller for isotactic than for atactic and syndiotactic PMMA. Large differences in the amts. of isolated PMMA were obsd. between melt-mixed and copptd. blends.