  We calculate the Witten index for 3d supersymmetric Yang-Mills-Chern-Simons
theories with matter. For N=2 theories, our results coincide with the results
of recent [1]. We compare the situation in 3d to that in 4d N = 1 theories with
massive matter. In both cases, extra Higgs vacuum states may appear when the
Lagrangian involves nontrivial Yukawa interactions between the matter
superfields. In addition, in 3d theories, massive fermion loops affect the
index via renormalization of the Chern-Simons level k.
