In this paper we study nonlinear elliptic boundary value problems with singular nonlinearities whose simplest example is −div (|∇u|p−2∇u)=f/uγ in Ω, u=0 on ∂Ω, where Ω is a bounded open set in RN (N≥2), γ>0, 10 and how the regularity of u depends on the summability of f, on p and on γ.