Abstract. We will prove a global estimate for the gradient of the solution to the Poisson differential inequality |∆u(x)| ≤ a|∇u(x)| 2 + b, x ∈ B n , where a, b < ∞ and u| S n−1 ∈ C 1,α (S n−1 , R m ). If m = 1 and a ≤ (n + 1)/(|u|∞4n √ n), then |∇u| is a priori bounded. This generalizes some similar results due to E. Heinz ([13]) and Bernstein ([3]) for the plane. An application of these results yields the theorem, which is the main result of the paper: A quasiconformal mapping of the unit ball onto a domain with C 2 smooth boundary, satisfying the Poisson differential inequality, is Lipschitz continuous. This extends some results of the author, Mateljević and Pavlović from the complex plane to the space.