Using specialized knowledge and perspectives of a set in decision-makings about issues that are qualitative is very helpful. Delphi technique is a group knowledge acquisition method, which is also used for qualitative issue decision-makings. Delphi technique can be used for qualitative research that is exploratory and identifying the nature and fundamental elements of a phenomenon is a basis for study. It is a structured process for collecting data during the successive rounds and group consensus. Despite over a half century of using Delphi in scientific and academic studies, there are still several ambiguities about it. The main problem in using the Delphi technique is lack of a clear theoretical framework for using this technique. Therefore, this study aimed to present a comprehensive theoretical framework for the application of Delphi technique in qualitative research. In this theoretical framework, the application and consensus principles of Delphi technique in qualitative research were clearly explained.