Let K[G] denote the
group ring of a (not necessarily finite) group G and suppose that this ring
satisfies a nontrivial polynomial identity of degree n. If Δ denotes the finite
conjugate subgroup of G, then we show that [G : Δ] ≦ n!. Furthermore,
if K[G] is semiprime, then G has an abelian subgroup of finite bounded
index.