AbstractDuring a survey carried out in Serbia in October 1998 and 1999 a population of Longidorus was found in forest soil from Mt Goch (central Serbia). The population was identified as a new species and is described herein as Longidorus cylindricapitatus sp. n. The new species is characterised by a body length of ca 5.5 mm, a vulva located almost at the mid-body (V − 50.5), an almost cylindrical lip region, amphidial pouches more or less symmetrically bilobed, a very long odontostyle (164–178 μm), and conoid tail with a rounded terminus. Males were not found. Data for the four juvenile stages are presented.