Isotropic hyperfine parameters of a set of vinyl radicals are investigated using the BILYP hybrid density functional. The systems studied are RHbetaCbeta=CalphaHalpha radicals, where R = H, BH2, CH3, NH2, OH and F. Theoretical results indicate that electronegativity of the substituent strongly affects the magnitude of hyperfine coupling with hydrogen nuclei as well as with C-13(beta) A(iso)(C-13(beta)) varies from -8.7 (4.9) to 17.4 G (-17.8 G) l`or Z (E) isomers of the radicals depending on the R group, BH2 and F, respectively. In the same order, for Z (E) isomeric forms A(iso)(H-1(beta)) diminishes from 40.1 (67.7) to 18.4 C (40.9 G) and A(iso)(H-1(alpha)) - from 25.6 (24.1) to 1.5 G (1.3 G). The effect of the substituents on the spin and electron density distribution is discussed in the framework of natural population analysis and theory of atoms in molecules.