We state a maximum principle for the gradient of the minima of integral functionals I (u)G Ω [ f (∇u)Cg(u)] dx, on ūCW 1,1 0 (Ω ), just assuming that I is strictly convex. We do not require that f, g be smooth, nor that they satisfy growth conditions. As an application, we prove a Lipschitz regularity result for constrained minima.