In this entry, which is part of the forthcoming European Encyclopedia of Private International Law (edited by Jurgen Basedow, Franco Ferrari, Pedro de Miguel Asensio, & Giesela Ruhl, Edward Elgar, forthcoming 2015), I explore jurisdiction to adjudicate (judicial jurisdiction) and the limits, if any, that international law imposes on the adjudicatory authority of nations and their courts. The limits, if any, that international law places on adjudicatory jurisdiction are open to debate. At the least, it seems clear that state practice and opinio juris do not limit many assertions of judicial jurisdiction. It also appears that general principles of law, outside of judicial jurisdiction being appropriate in a defendant’s place of domicile, are still not fully developed. It is also questionable whether the idea of reasonableness has reached the level state practice and opinion juris under international law to limit assertions of judicial jurisdiction. For these reasons, it is far too soon to conclude that international law places meaningful limits on judicial jurisdiction and assertions of exorbitant jurisdiction. Such a conclusion does not take sides on the normative question of whether international law should limit assertions of adjudicatory jurisdiction. Rather, it is a conclusion based on the practice of nations and their courts at present. The current American Law Institute project on the Restatement (Fourth) of the Foreign Relations Law of the United States will, no doubt, have much to say on these matters. Yet, no matter what conclusion the new Restatement comes to, its approach will have to be proven by the general acceptance of states.