Legal institutions are norms and laws that are considered important to support activities in the community. With it, peace and tranquility are created and good habits of behavior are created. MUI is a place to complain for Muslims in Indonesia about matters related to problems in society. With the fatwa produced by the MUI, it will answer the needs of Muslims, its existence can also help ease the task of the government. This study uses a qualitative descriptive research method, with a literature approach. The results of the study state that in legal institutions, the fatwa of the MUI ulama can become legally binding if it is formalized into laws or derivative regulations under it.Keywords: Islamic Law Institutions; Fatwa; MUI Abstrak:Pranat...