This Ph.D. thesis deals with creating an algorithm for stochastic optimization of the cross-sectional parameters of flat frames. After a brief introduction and outline of the thesis' goals is the summary of knowledge and results in the areas of deterministic and stochastic structural optimization. Further, the task of deterministic optimization is described, as it was solved in the previous thesis and papers which this thesis follows up on. Afterwards, the reformulation of the deterministic task to its stochastic form is described and the solution algorithm for such a task is introduced. The thesis ends with results of using the introduced algorithm on 6 examples.