This thesis seeks to explore the relationship between indirect expropriations and regulatory measures. Expropriations mostly occur in the form of indirect expropriations, where a state’s regulatory measures cause the investor to lose any benefit it has in its investment. However, it is difficult to distinguish indirect expropriations from regulatory measures that do not require compensation. How this difficult balance is maintained will be explored in this thesis. This thesis first focuses on the key notions of expropriation and regulatory measure. It then explores the different ways the relationship between expropriations and regulatory measures is approached before elaborating on the criteria that are used to distinguish indirect expropriations from non-compensable regulatory measures. Finally, this thesis addresses indirect expropriations with environmental concerns.