AbstractThis paper concerns the extreme structural response analysis of truss structures taking the possible uncertainties of Young's moduli of the bars into consideration. The uncertainty of Young's modulus is described by a non‐probability but bounded interval model. With the use of this uncertain model, it is shown that the structural responses such as nodal displacement and bar stress will attain their extreme values when Young's moduli of the bars take either their upper or lower bound value. Based on this conclusion and simultaneous analysis and design formulation, a linear mixed 0–1 programming problem can be constructed to find the extreme values of the structural response by the well‐established branch‐and‐bound approach with global optimality. The proposed approach is applied to several test problems for the demonstration of its validity. Copyright © 2008 John Wiley & Sons, Ltd.