Jesper Tidblom A geometrical version of Hardy's inequality for W^{1,p}_0(D) (34K, LaTeX 2e) ABSTRACT. The aim of this article is to prove a Hardy type inequality, concerning functions in W^{1,p}_0(D) for some domain D in R^n, involving the volume of D and the distance to the boundary of D. The inequality is a generalization of a recently proved inequality by M.Hoffmann--Ostenhof, T.Hoffmann--Ostenhof and A.Laptev, which dealt with the special case p=2.