The fork-in-the-road clauses in bilateral investment treaties provide for a right for the plaintiff to apply to the national courts of the host state or to arbitration as regards disputes arising from such treaties. However under such clauses, by initiating proceedings before the court or tribunal the plaintiff makes an irrevocable choice, thus, once one of the dispute resolution mechanisms is initiated by the plaintiff, then he is bound by his choice. As such the fork-in-the-road clauses not only regulate the relationship between different methods of dispute resolution but are also accepted as a tool against parallel proceedings that may arise from taking the same action before different courts and tribunals. In fact the main question is whether the plaintiff must be deemed to have exercised his choice under such a clause by bringing any action before the courts of the host state. This paper aims to determine the answers to this question as regards decisions given by International Centre for the Settlement of Investment Disputes (ICSID) arbitral tribunals. In this regard decisions of Alex Genin, Eastern Credit Limited, Inc. and A.S. Baltoil Genin v Republic of Estonia of 2001 and Pantechniki S.A. Contractors & Engineers (Greece) v Republic of Albania of 2009 shall be explained and discussed as the main examples of two different approaches.