We extend the large N duality of four dimensional N = 1 supersymmetric Yang
-Mills theory with additional chiral fields and arbitrary superpotential re
cently proposed by Cachazo, Intriligator and Vafa to the case of SO / Sp ga
uge groups. By orientifolding the geometric transition, we investigate a la
rge N duality between N = 1, SO / Sp supersymmetric theories with arbitrary
superpotential and an abelian N = 2 theory with supersymmetry broken to N
= 1 by electric and magnetic Fayet-Iliopoulos terms.