The right to freedom of religion is one of the fundamental rights guaranteed in many international and regional human rights instruments. Several international documents safeguard freedom of religion including the right to convert from one faith to another. In Malaysia, the safeguard of this fundamental right is provided under Article 11(1) of the Federal Constitution with some limitations. The right to convert out of one’ s faith is not mentioned explicitly. However, for the non- Muslims, this right to opt out of one’ s faith and choose another has been regarded as an implicit part of religious liberty guaranteed by Article 11. In relation to the Muslims, the issue of apostasy is regarded as a taboo as well as a politically explosive proposition. This paper aims to examine the concept of freedom of religion under international law focusing mainly on the issue of apostasy in the context of the Malaysian Federal Constitution. The paper concludes that the position of Muslims especially in the context of embracing a new religion remains unsettled.