Abstract. We prove new velocity averaging results for second-order multidimensional equations of the general form,These results quantify the Sobolev regularity of the averages, v f (x, v)φ(v)dv, in terms of the non-degeneracy of the set {v : |L(iξ, v)| ≤ δ} and the mere integrability of the data,Velocity averaging is then used to study the regularizing effect in quasilinear second-order equations, L(∇ x , ρ)ρ = S(ρ) using their underlying kinetic formulations, L(∇ x , v)χ ρ = g S . In particular, we improve previous regularity statements for nonlinear conservation laws, and we derive completely new regularity results for convection-diffusion and elliptic equations driven by degenerate, non-isotropic diffusion.