As a new entity, ISIL has carried out the most violent actions under the flag of Islam and pursued the idea of forming “Welayat-i-Khorasan” in its governmental vision. According to this perspective and subsequent steps such as the announcement of the existence of ISIL raises the question of what implications the strengthening of ISIL's presence in Afghanistan will have for the national security of the Islamic Republic of Iran. Based on the Delphi method as one of the well- known techniques in futures studies, the paper has tried to explore different aspects of the issue by taking advantage of the opinions of elites and prominent experts of Afghanistan affairs. In order to answer the above question, seventeen experts on Afghanistan issues who were selected through the Snowball sampling method answered questions about the various aspects of this issue during four Delphi rounds and out of 19 questions, 14 of them came to a consensus. The findings indicate that the strengthening of the presence of ISIL threatens the national security of the Islamic Republic of Iran both domestically and internationally. Opportunities such as expansion of technical and intelligence cooperation or establishing regional and international arrangements are likely subject to do so, but are not significant in comparison to the threats posed. Also, regarding the current differences in the form and nature of ISIL's presence in Syria and Afghanistan, it seems that not only Iran cannot choose the exposure method of Syria but also must not do so.