Let R be a Noetherian local ring, I and J two ideals of R and let M be a nitely generated R-module of dimension n. We study the top local cohomology module Hn I;J (M) with respect to a pair of ideals (I; J). It is proved that AttR Hn I;J (M) = fp 2 AssRM : cd(I; J;R=p) = ng, where cd(I; J;R=p) is the supremum of all integers i for which Hi I;J (R=p) 6= 0.
