Abstract: Because of the relatively high slenderness of castellated beams and significant area of the openings in the web, one of the possible failure modes is the lateral-torsional buckling. The simplified verification of the resistance for the lateral-torsional buckling is proposed in [ 1 ], which implies the similar calculation for the lateral-torsional buckling as for the standard plate beams but with the reduction of geometrical characteristics of cross-section.