This paper lists and reviews the archaeological evidence for the Sasanian period in eastern Arabia (third–seventh centuries AD). Much of the published evidence is shown to be either erroneous or highly doubtful, leaving very little evidence that is reliable. It is argued that the paucity of evidence in comparison to the Hellenistic/Parthian period indicates that this was a time of marked and continuing decline in the number and size of settlements, the number of tombs and the amount of coinage in circulation, all of which probably result from a population that was both declining in size and participating less in the types of production and consumption that leave discoverable traces in the archaeological record. This is in contrast to the historical evidence, which, although patchy, is stronger for the Sasanian period than it is for the Hellenistic/Parthian period. The argument for decline challenges some generally accepted historical views of eastern Arabia at this time, which see the region as undergoing a notable period of growth. In conclusion, some brief consideration is given to the possible causes of the decline.