A new species of intertidal acorn barnacle Tetraclita ehsani sp. n. was identifed from the Iranian coast in the Gulf of Oman. T. ehsani sp. n. inhabits low exposed rocky shores and also attaches to shells of molluscs and the barnacle Megabalanus species. Parietes of T. ehsani ranged from white to pink which is diferent from T. serrata (in South African waters), which has green parietes. Morphology of the tergum and cirrus III of T. ehsani sp. n. is distinctive from other described West Indian Ocean species which have pink or white parietes (T. rufotincta, T. achituvi and T. reni). Te tergum of T. ehsani is very narrow and the basal margin is slightly concave or straight, in contrast to T. rufotincta and T. reni, in which the tergum are board and with a very concave basal margin. Cirrus I anterior ramus of both T. ehsani and T. reni is anten-niform and thus difering from the cirrus I of T. rufotincta (see Chan et al. 2009). Cirrus III of T. ehsani sp. n. is non-antenniform and lacks multicuspidate type setae, which is diferent from T. reni by having an antenniform cirrus III and with multicuspidate setae.