The ammonites from upper Coniacian to middle to upper Santonian of the Siah-Kuh section in Zagros basin, west of Iran have been described and illustrated. Three ammonite species from the argillaceous limestones of the Ilam Formation of the Bangestan Group are recognized. These ammonite species consist of Texanites (Texanites) gallicus Collignon, 1948, Texanites rarecostus Collignon, 1966 and Protexanites (Protexanites) cycni van Hoepen, 1965. These identified ammonite taxa are recorded from Iran for the first time. According to these ammonite species, first 100 m of the Ilam Formation dated as upper Coniacian to middle Santonian. There is no ammonite evidence for the upper part of the Ilam Formation which dated as upper santonian-lower Campanian at the type section by Chahardah-Cherik, 2006.