New structural steels, such as (liquid) quenched and tempered (QT) steels, with extra high strength, good toughness and weldability have been developed in Europe in recent years and are included in Eurocode 3 Part 1-12 for strengths up to S 700. However, extra high strength steels (EHSS) with a yield strength of 1100 N/mm2 so far have not been taken into account in the present version of Eurocode 3 due to insufficient knowledge on their buckling behaviour and fatigue strength and lack of associated experimental data. In this article results of experimental and numerical investigations concerning the local buckling behaviour of cold-formed and welded hollow sections made of EHSS are summarised. The investigations have been carried out within the scope of an European research project. Results have been used to check the applicability of existing design rules for local buckling to EHSS. As a consequence the scope of Eurocode 3, Part 1.12 could be expanded to cover stability rules also for such steels.