Mithraism was a mystery religion centered on the god Mithras that was practiced in the ancient world including India, Iran, Anatolia, Etc. There is still much uncertainty about its nature and its origin, despite numerous documents such as the most ancient religious books of the world including the Avesta and Rig Veda, and the oldest inscriptions including: Boğ azkö y and Achaemenid inscriptions, and finding hundreds of temples in the territory of ancient Rome. One of the ambiguities is that how the temples of this religious tradition were built in Iran. The main question here is that “ is there any possible similarities in Iranian temples to the European types or not? ” To investigate the question, the plans and architectural spaces and components of the Mithra temples are compared using inductive methods and library studies in two civilizations that are altogether different in terms of their environmental and cultural conditions. The research hypothesis emphasizes the difference between the Roman Mithra temples and Iranian types. Despite that, they have a unique root; however, they have some imagined similarities. Finally, it was found, that different environmental conditions gave rise to a different understanding of religion, and so on. The main purpose of the article is to study and introduce several Iranian Mithra temples. The plan of the Roman temples is rectangular, but a study of the Iranian temples of Abā zar, Varjuvi, and Bā dā miyar (Qadamgā h) showed that the most of them had a dome-shaped space with a circular plan and their walls lacked paintings and sculptures. Nevertheless, as Herodotus has already described, the Qarashirā n temple has square plan in the meantime; such Iranian temples lack authentic decorations inside and out. The results of the research show that what was depicted in the European Mithra temples, was performed during a special ceremony in Iran; a point that all artistic and written sources acknowledge.