Abstract. The purpose of this paper is to exhibit fine structure for polyhedral products Z(K; (X, A)), and polyhedral smash products Z(K; (X, A)). Moment-angle complexes are special cases for which (X, A) = (D 2 , S 1 ) There are three main parts to this paper. (1) One part gives a natural filtration of the polyhedral product together with properties of the resulting spectral sequence in Theorem 2.15. Applications of this spectral sequence are given. (2) The second part uses the first to give a homological decomposition of Z(K; (X, A)) CW pairs (X, A). (3) Applications to the ring structure of Z(K; (X, A)) are given for CW-pairs (X, A) satisfying suitable freeness conditions.