The objective of paper is to create an Islamic accountability index of cash waqf institution in Indonesia. Cash waqf is a new phenomenon in Indonesia since the Act was just issued in 2004. Some new cash waqf institutions were established but unfortunately without tight monitoring from the government. An accountability index can show the reported activity of cash waqf institution. This may help society to see the accountability condition of the institution. Research method conducted is based on qualitative method with literature review. In-depth interview is added to confirm and to enrich the index analysis. The index is tested to cash waqf institution based on web basis. The result may show that accountability index may describe some activities and financial report of cash waqf institutions. Most cash waqf institutions have not high index for the accountability. This may be caused by limited support of the cash waqf institutions to show their accountability. Cash waqf institutions should prepare the supported information system to show the accountability especially in the online system.