For FE-based structural optimiza.tion systems, a. large variety of different numerical algorithms ia ava.i\able, e.g. sequential linear programming, sequential quadratic programming, convex approximation, generalized reduced gradient, multiplier, penalty or optimality criteria. methods, and combina.tions of these approaches. The purpose of the pa.per is to present the numerical reaults of a comparative study of eleven rnathematical programrning codes which represent typical realizations of the mathema.tical methods mentioned. They a.re implemented in the structural optimization system MBB-LAGRANGE, which proceeds from a typical finite element analysis. The comparative results are obtained from a collection of79 test problems. The majority ofthem are academic test cases, the others possess some practical reßlliJe background. Optirnization is performed with respect to sizing of trusses and bearns, wall thicknesses, etc., subject to stress, displacement, and many other constraints. Numerical cornparison is based on reliability and efficiency measured by calculation time ana number of analyses needed to reach a certain accura.cy level.