We show that a first order perturbation A(x) · D + q(x) of the polyharmonic operator (-Δ)m, m ≥ 2, can be determined uniquely from the set of the Cauchy data for the perturbed polyharmonic operator on a bounded domain in ℝn, n ≥ 3. Notice that the corresponding result does not hold in general when m = 1. © 2013 American Mathematical Society.