Two-ply laminated architectural glass used in automotive industry since 1914, now become an important element in construction industry as well. Regarding its importance, a theoretical model is needed for the laminated glass beams investigated mostly experimentally so far. In this paper, a mathematical model for the behavior of laminated glass beams is introduced. The minimum total potential energy principle is employed in developing the mathematical model by assuming large deflection for a laminated composite beam since glass beams are very thin. The model is then validated by the experimental and finite element models for the simply and fixed supported beams respectively. It is presented that the behavior of laminated glass beams under large deflections could be linear or nonlinear regarding the boundary conditions or constraints. (c) 2005 Elsevier Ltd. All rights reserved.