The purpose of this study is to examine aspects of internal quality assurance to evaluate Indonesian Islamic universities, develop Delta Internal Quality Assurance (DIQA), and provide empirical evidence for using DIQA as a standard model of evaluation. It is a research and development (R&D) endeavor in the context of the input, process, and product. This study applies four cycles, namely exploration, preliminary testing, main field testing, and main operational testing, and the development process took place through a two-round Delphi method. In terms of findings, the study presents a prototype instrument named DIQA, which is subsequently refined though the main field and operational testing phases. It is then processed using CFA and LISREL statistical analysis to determine its validity and reliability. The final version of DIQA accommodates seven dimensions of evaluation, 10 sorts of questionnaire, and 477 question items. The implication is that DIQA will help face the challenge of aligning with the national accreditation system set by the government. It follows that DIQA should be publicly and disseminated, and Islamic universities should be encouraged to use DIQA confidently. In terms of originality and value, DIQA has the special property of promoting Islamic values in the internal quality assurance, which is important to the specific properties of Islamic universities in Indonesia.