During Tun Dr. Mahathir Mohamad served as a Prime Minister of Malaysia, some efforts are shown when he trying to evaluate the current economic system which is based on the conventional economic system and trying to change to the Islamic economic system. This is caused by the evolution from the westernized thought to the Islamic thinking that occurred by a paradigm shift of people who was more interested in switching to the Islamic economic system. However, it's weird because this thought is differ from Tun Dr. Mahathir Mohamad's leadership who is deemed to be more westernized than Islamic ways. In the meantime, Tun Dr. Mahathir Mohamad also had implemented the Dasar Penerapan Nilai-nilai Islam policies and he had declared Malaysia as an Islamic state. The problem is, the economic development is mixed between the conventional economic development and the Islamic economic development. It is being an issue because when the people are taught to use the Islamic economic system? Is that the outcome from the implementation of the Dasar Penerapan Nilai-nilai Islam by Tun Dr. Mahathir Mohamad's leadership? What are the Islamic economic criteria has been used by Tun Dr. Mahathir Mohamad to attract the people? In order to answer the above questions, this paper was written to answer these questions by examining and analyzing the implications of the Tun Dr. Mahathir Mohamad's leadership in the Islamic economic development in Malaysia. The methodology has been used for this paper are using the literature review method and content analysis method. The results shows during Tun Dr. Mahathir Mohamad served as Prime Minister of Malaysia, he has been attempting to develop the Islamic economic system in Malaysia. Tun Dr. Mahathir Mohamad also approached the Saudi Arabia to get the information and an experience from their implementation economic system based on shari'ah. Interestingly, although the implementation of the Islamic economic system is already started in Malaysia, the positions of non-Muslims in the country are not affected at allÂ