An extensive study is presented of nuclear spin-spin coupling constants in 25 polyhedral boranes using density functional theory/finite perturbation theory (DFT/FPT) methods to determine the Fermi contact term. Scalar couplings were obtained at either the UB3LYP/6-311G** or the UB3LYP/6-311(++)G** level, with molecular structures fully optimized at the B3LYP/6-31G* DFT level. The calculated results are in good agreement with the solution experimental data for a wide range of directly bonded, geminal, vicinal, and long-range coupling constants. The largest disparities occur for (1)J(B-11-H-1) and (1)J(C-13-H-1) values greater than 120 Hz. These are underestimated on average by about 5%, a value close to that expected (4%) from the effects of motional averaging on directly bonded coupling constants. The accurate prediction of coupling constants in polyhedral boron compounds will be extremely helpful in their detailed NMR spectral analyses.