The article is devoted to the evaluation of the torsional stiffness of the beam-pillar nodal connection of thin-walled rack structures. Results of in-place testing of several girder rack models are described, beam model and combined one are considered. Computational finite element (FE) models of these racks are designed to develop a FE analysis by software complex ANSYS. Assessment of the torsional stiffness of the beam-pillar nodal connection in these structures is obtained by comparison of results of computation and experimental ones. Critical buckling load for the first buckling mode is determined both experimentally and computationally. Buckling modes of “out of the face plate” and “in the face plate” are considered. The influence of the torsional stiffness of the beam-pillar nodal connection on bearing capacity and buckling stability of thin-walled rack structure is investigated. Correspondence of these characteristics and number of tiers is revealed.