Two bands of the A (IIu)-I-2<--X(2) Sigma(g)(+) transition of Si-2(-) lying in the mid-infrared region have been detected using diode laser velocity modulation spectroscopy. The anion was generated in an air cooled low pressure ac discharge through mixtures of silane and hydrogen, and 130 Lines of the (1,0) and (2,0) bands lying between 670 and 810 cm(-1) and 1200 to 1340 cm(-1) respectively were measured and assigned. A fit to standard Hamiltonians for (2) Sigma and (II)-I-2 states yielded the most precise spectroscopic constants so far obtained for the anion. These have been used to derive several equilibrium parameters for the A state. The equilibrium internuclear distance of the A state is r(e)=2.182986(16) Angstrom. The fine structure and equilibrium parameters are compared with earlier low resolution results and with ab initio calculations on Si-2(-).