Under study is a special class of mixed-integer bi-level programming problem (BLPP) which arises in several areas such as engineering, transportation and control systems. The main characteristic of BLPP is that the outer optimization (upper level) problem is constrained by an inner optimization (lower level) problem. In this paper, a Lagrangean relaxation method is proposed to obtain an acceptable feasible solution by solving a sequence of one-level mixed-integer problems. The computational results on some examples were taken from literatures and randomly generated problems indicate that the method is able to solve the BLPP efficiently.
