A particular doctrine will be declared as deviant teaching if it contains heretical elements that are clearly against the Islamic faith. The Muzakarah Committee of the National Council for Malaysian Islamic Affairs (MKI Muzakarah Committee) and the State Mufti Department have issued several legal views and fatwas on misleading practices that clearly contradict with Islamic teachings due to heretical elements found in particular deviant groups. Hence, this article aims to analyze the heretical teachings in some deviant groups that have been gazette for ban in Malaysia. This study uses document analysis method with reference to views of the law and fatwas issued involving heretical teachings which have been gazetted for ban in Malaysia. There is strong evidence on existence of heretical elements and misleading practices by the studied deviant groups, thus causing them to be gazetted as heretical groups that clearly deviate from the true teachings of Islam. Accordingly, this work is a significant study to explain the threats of heretical teachings to Islamic teachings and Muslim society as a whole, realizing that deeds of Muslim believers in principle will not be accepted if their practice clearly contradicts with the Islamic faith