The article offers a survey of temple architecture in the Iranian world before the Macedonian conquest. Despite the observations that ancient Iranians worshipped in the open air, structures of cultic significance have been discovered in some areas of Eastern Iran. While the attribution of the earliest, second millennium temples to the Iranian tribes is still disputable, Iranians definitely had temples before the Achaemenids. The earliest temples found in the Iranian settlements are the ones from Tepe Nush-i Jan (for Western Iran) and Dahān-i Ghulāmān (for the Eastern). However, it seems that the majority of ancient Iranians, including the first Achaemenids, worshiped under the open sky. Given the nomadic background of the ancient Iranians they probably became acquainted with temple architecture once they came into close contact with the highly developed civilisations, which preceded them in some areas of what was later to become the Iranian World. In general it is impossible to speak of one “Iranian culture” or a unified “Iranian cult” in the second and first millennia BCE; instead, temple architecture demonstrates a variety of different regional traditions. More temples have been discovered in Eastern Iran than in Western. The architectural evidence from Eastern Iran in this period also suggests a complex picture of heterogeneous local cults, at least some of which made use of closed temples. Another kind of cultic structure was the open air terraces. There is also some evidence for domestic cults. Iranian cults also share a number of common, dominant features. Special significance was attributed to fire and ashes. Most temple altars (often stepped) were at the centre of the cult and rituals. Another important feature is the absence of cult statues and images. It is remarkable that most of the temples were erected on the highest point of the site or on an artificial elevated platform.