Finding a feasible solution for a bi-dimensional Orthogonal Packing Problem (OPP2) consists in deciding whether a set of rectangular boxes (items) can be packed in a "big" rectangular container without overlapping. The rotation of items is not allowed. In this paper we present a new algorithm for solving OPP-2, based on the characterization of solutions using interval graphs proposed by Fekete and Schepers. The algorithm uses MPQ-trees - combinatorial structures introduced by Korte and M