The present work aims to investigate the interaction between lateral torsional buckling and compression tee local buckling in castellated beams. The finite element method (FEM) is used to perform a parametric study for Litzka-beams subject to pure bending moment considering combinations of flange-to-web width and thickness ratios and unbraced lengths. To account for the possibility of different yield strengths, non-dimensional local and global slenderness are used to assess the behavior in a comprehensive manner. The responses for beams having different combinations of slendernesses are compared and the relative strengths are discussed. The influence of the initial imperfections on the strength capacity is evaluated. The FEM ultimate bending moments are compared to those calculated according to the current design recommendations for castellated beams, showing that these may either over or underpredict actual capacities. Finally, a direct strength method approach is tested for the prediction of the nominal bending strength. Through the performed analyses it was concluded that the Design Guide underestimate the relative strengths of the analyzed geometries, while the direct strength method overestimated them and the initial imperfections influence the structural behavior of the analyzed beams.