The thesis takes a look at the complex legal framework, set forth mainly by BITs and the ICSID convention, but also a number of other treaties and principles of international law are touched upon. Worth mentioning are the Vienna Convention, the New York Convention and awards based on the UNCITRAL rules. Since ICSID tribunals handle most of the treaty-based investment arbitrations conducted, ICSID awards would best explain the rules, which is likely to create standards followed by other types of treaty based arbitration. A number of ICSID awards are examined and the aim is to analyze and find out to what extent an arbitral award or an arbitration agreement can meet the requirements of an investment and attempt to find out the real place for international commercial arbitration within investment treaty arbitration. The main focus is the situation under the ICSID regime, but the legal frameworks for International Investment Arbitration are very much intertwined, so awards and legal theory which are not only limited to disputes under ICSID are also discussed.