A new species of the genus Acrobeles is described from natural areas in Tehran province, Iran. Acrobeles iranicus sp. n. is characterised by having a body 400–441 μ m long in females, 'double' cuticle with rows of interannular punctations, lateral field with two incisures, labial probolae 9–12 μ m long, pharyngeal corpus slightly fusiform and 2–4 times isthmus length, postuterine sac 5–15 μ m or 0.2–0.5 times as long as body diam. and bearing larger cells in its proximal part and conical female tail (31–36 μ m, c = 11.5–13.6, c′ = 2.3–2.9). In addition, Iranian populations of another three previously known species are studied: A. andalusicus, A. complexus and A. singulus, the third species having the male described for the first time. Descriptions, measurements and illustrations, including SEM photographs, are provided for all four species.