As one of the most extensive prehistoric entities of western Iran, Dalma culture belonging to the Zagros Chalcolithic, flourished in vast areas of the Central Zagros and Northwest Region of the country. This culture is defined essentially by its characteristic ceramic assemblages that show a marked uniformity in terms of technology, vessel forms, and painted designs throughout its territory. One of the main issues regarding this culture is its chronology, which was largely based on comparative studies, a few radiocarbon (14C) dates analyzed in the 1960s–1970s, or a few confusing thermoluminescence dates. In this paper, a series of 15 charcoal samples from a recent salvage excavation at Nad Ali Beig, a single-period site dated to Dalma period, is presented that provide the first reliable absolute dates for a part of the Middle Chalcolithic period of the Central Zagros region. Based on these new dates we may suggest that Dalma culture flourished between ca. 5200/5100–4600 BCE. Furthermore, based on these dates it is now possible to determine the order of appearance of different types of the Dalma culture ceramic assemblage, including the Ubaid-related painted buff ceramics.