Duality of Sp(2N$_{c}$) and SO(N$_{c}$) supersymmetric gauge theories with adjoint matter

We discuss electric-magnetic duality in two new classes of supersymmetric Yang-Mills theories. The models have gauge group Sp(2\nc) or SO(\nc) with matter in both the adjoint and defining representations. By perturbing these theories with various superpotentials, we find a variety of new infrared fixed points with dual descriptions. This work is complementary to that of Kutasov and Schwimmer on SU(\nc) and of Intriligator on other models involving Sp(2\nc) and SO(\nc).