Two stratigraphic sections in the Chaman-Bid Formation east of Mashhad have been measured and their ammonite fauna studied. These comprise 11 taxa coming from Narband and Radar sections. Based on ammonites the stratigraphic range of the Chaman-Bid Formation at Narband section is Bathonian to Oxfordian and at Radar section late Bajocian to Callovian. The ammonite fauna cor-responds more or less to those reported from Alborz and Central Iran, which indicates that the basins of Koppeh-Dagh, North and Central Iran were con-nected to each other. The studied ammonite fauna shows close relations to the same-aged ammonites of Europe, especially to the Sub-Mediterranean Province.