This book constitutes of research Project Paper submitted by the author as part of requirement for graduating with Master of Laws (LLM) Degree from the University of Nairobi in November 2019. The research was done under the supervision of Professor Francis D. P Situma of the School of Law, Parklands Campus of the University of Nairobi. The question the book attempts to answer is whether treaties that were ratified, and not domesticated, when the Constitution of Kenya, 2010 was promulgated on 27 August, 2010, can be applied as law under Article 2(6) therein. Article 2(6) provides that ratified treaties form part of the law of Kenya. It is argued that such treaties were not law in Kenya when the Constitution was promulgated and they can, therefore, not be implemented. It is recommended that the safe way of ensuring the treaties are implemented is by domesticating them. This will bring them under the current constitutional order in Kenya and in line with the principle of pacta sunt servanda.