: The (6,0)[16.0]1.5 X-2 Delta(5/2) and (7,0)[16.0]3.5-X-2 Delta(5/2) bands of IrSi have been recorded using high-resolution laser-induced fluorescence spectroscopy. The field-free spectra of the (IrSi)-Ir-191 and isotopologues were modeled to generate a set of fine, magnetic hyperfine, and nuclear quadrupole hyperfine parameters for the X-2 Delta(5/2)(v = 0), [16.0]1.5(v = 6), and [16.0]3.5 (v = 7) states. The observed optical Stark shifts for the (IrSi)-Ir-193 and (IrSi)-Ir-191 isotopologues were analyzed to produce the permanent electric dipole moments, mu(ev) of -0.414(6) D and 0.782(6) D for the X-5/2(2 Delta) and [16.0]1.5 (v = 6) states, respectively. Properties of the X2 Delta(5/2) state computed using relativistic coupled-cluster methods clearly indicate that electron for achieving good accuracy for the nuclear quadrupole coupling parameter eQq(0).