AISC Design Guide 31 proposes the same procedure used for calculating the lateral torsional buckling strength of plain webbed beams be used for castellated beams during both construction and utilization stages. The basis for these provisions is an experimental program which tested 24 samples of two different castellated beam sections with the aim of determining the critical unbraced length of these beams during construction . This paper examines the validity of the Design Guide's provisions by comparing it against the experimental results. It is found that the Design Guide's provisions and the experimental results conflict, with the Design Guide's provisions yielding highly unconservative results . This discrepancy in results arose from an arithmetic blunder in the calculations of the experimental program. An alternate procedure is presented to rectify the Design Guide's provisions.