A simplified procedure for determining approximate values for the buckling loads of three-dimensional framed structures is developed. The procedure utilises lateral load analysis of structures and yields error-, less than 10%, which may be considered suitable for design purposes. The structures with or without rigid floor diaphragms may be considered readily. Bucklin.- loads of both regular and irregular structures may be obtained. The proposed procedure is applied to several numerical examples and it is shown that all the errors are in the acceptable range and generally on the safe side. Determining the buckling loads of structures using SAP2000 is also discussed. (c) 2006 Elsevier Ltd. All rights reserved.