It is an institution formed of two complexes, including the Museum of Ancient Iran (Muze ye Irān e Bāstān) which was inaugurated in 1937, and the Museum of the (post-) Islamic Era (Muze ye Dowrān e (pasā) Eslāmi) which was inaugurated in 1972.
It hosts historical monuments dating back through preserved ancient and medieval Iranian antiquities, including pottery vessels, metal objects, textile remains, and some rare books and coins.
There are a number of research departments in the museum, including Paleolithic and Osteological departments, and a center for Pottery Studies.
The brick building of the Museum of Ancient Iran was designed by the French architect Andre Godard in the early 20th century. It was influenced by Sassanid vaults, particularly the Eyvān e Kasrā at Ctesiphon. With an area of approximately 11000 square meters, its construction began in 1935 and was completed within two years by Abbas Ali Memar and Morad Tabrizi. The complex was officially inaugurated in 1937.
The later constructed Museum of the (post-) Islamic Era was built with white travertine on the grassy grounds of the Museum of Ancient Iran. It has gone through quite a few hasty interior changes, and was still being remodeled when the 1979 Revolution swept the country.
While the Museum of Ancient Iran always had a clear mandate to show archaeological relics, as well as some rare medieval textiles and rug pieces, the newer building began to also feature the exquisite Amlash pottery from the prehistoric Caspian Sea regions of Iran. This was followed by some modern arts, and the repeated gutting and remodeling of the interior.
The older building consists of three halls. The halls contain artifacts and fossils from the lower, middle, and upper Paleolithic, as well as the Neolithic, Chalcolithic, early and late Bronze Age, and Iron Ages I-III, through the Median, Achaemenid, Seleucid, Parthian, and Sassanid periods.
Plans are underway for the construction of another building, as the current ones lack the capacity and standards for preserving all of the excavated treasures. The collection amounts to 300,000 artifacts.