The chapter assesses the level of internalisation of investment treaty obligations in Sri Lanka as well as their impact on the rule of law. The findings of this paper reveal that though there is some awareness of Sri Lanka’s investment treaty obligations at the level of some of the higher level state organs considered, there are no processes in place to systematically consider those obligations, particularly at the lower levels of government in interactions with investors. The legislative process is a significant exception to this observation due to the unique protection given to investment treaty obligations under Article 157 of the Constitution. Furthermore, despite the awareness of at least the existence of investment treaty obligations at some levels of government, the impact of such obligations on domestic decision- making appears minimal, with political considerations playing a large part in such decisions, sometimes in spite of the state’s investment treaty obligations. Given that there is minimal internalisation of investment treaty obligations, the chapter concludes that there has been minimal spill-over effect of such obligations on the rule of law in general.