Isotropic and anisotropic hyperfine coupling constants for the series C2HnF5-n, n = 0-5, have been calculated using density functional theory, at the local spin density and gradient corrected levels, using the IGLO-III basis set on previously reported MP2/6-31G(d,p) optimized geometries. In most of the cases where comparison with experiment is possible, the agreement ranges from good to excellent for the gradient corrected results. whereas the local spin density results are less accurate, as expected. For a few radicals similar calculations were performed on geometries optimized with density functional theory, but only minor changes were noted in the results. The magnitudes of the couplings correlate well with the degree of pyramidalization at the radical center, indicating a larger degree of s character of the SOMO at these nuclei, and hence a larger spin density, through the increased sp(3) hybridization.