The laser induced fluorescence spectra of the B (3) Pi(0(+))<--X(1) Sigma(+) electronic transition of (ICl)-Cl-35 and (ICl)-Cl-37 have been recorded with a linewidth of similar to 5 MHz. This resolution allows the hyperfine splittings due to both nuclei to be measured. We report values for eQq(0)(I) and eQq(0)(Cl), for both (ICl)-Cl-35 and (ICl)-Cl-37, for v’ = 0-2 and v" = 0-2. This provides new data for both the ground and excited states. Information on the ionic character of the chemical bond of ICl in the X and B electronic states was deduced using a single electronic configuration [linear combination of atomic orbitals/molecular orbital (LCAO/MO)] model. The ionic character (fractional charge transfer) of the X state is -0.24 for v" = 2, 1% less than for v" = 0. Since the pi and pi* orbitals are completely filled for the X state, this ionic character is due entirely to the a bonding orbital. For the B electronic state, the total ionic character was estimated from the dipole moment, and the hyperfine data were used to separately determine the ionic character of the a type and pi type molecular orbitals (-0.13 and -0.14, respectively). This is qualitatively consistent with the predictions given by the LCAO/MO model. However, the ionic character of the pi type orbitals is observed to change rapidly with vibrational excitation, with the magnitude tending to zero at v’ = 2.