So far WTO jurisprudence has not resolved the puzzle of how WTO Members that are part also of a regional trade agreement (such as NAFTA or MERCOSUR) should conduct safeguard investigations and apply eventual safeguards in line with WTO rules. Can or must they exclude regional imports from the injury determination? Can or must they apply the eventual safeguard only to third parties, or are they under an obligation rather to apply all safeguards on a non-discriminatory basis? Those are the questions examined in this paper. The paper refocuses some of the attention to GATT Article XIX and criticizes the Appellate Body’s requirement of parallelism as well as its jurisprudence under GATT Article XXIV. It also offers an alternative way forward and ends with a list of options for WTO safeguards by members of customs unions or free trade areas.