The Panel on Plant Health performed a pest categorisation of Xiphinema californicum (Nematoda: Longidoridae) for the EU. The nematode is a well-defined taxon belonging to a group of morphologically similar species called Xiphinema americanum sensu lato. The nematode was described from the USA and is present in some North and South American countries. The nematode is not present in the EU and is regulated by Council Directive 2000/29/EC, listed in Annex I A I as X. californicum Lamberti and Bleve-Zacheo. It is a polyphagous pest found in soil associated with a number of plant species. As a migratory ectoparasitic species, it punctures the cells of plant roots. X. californicum is in principle able to cause direct damage to plants, but its main damage is caused by vectoring the American nepoviruses: Tobacco ringspot virus (TRSV), Tomato ringspot virus (ToRSV) and Cherry rasp leaf virus (CRLV). Soil is a potential pathway for this nematode for entry into the EU. Moist soil, such as soil attached to plants for planting, increases survival of the nematode. The viruses may persist over prolonged periods inside the nematode and viruliferous nematodes may introduce American nepoviruses. Climatic conditions in the EU are similar to those found in the areas where the pest is currently present. Hosts of the nematode (and of associated viruses) are, e.g. grapes, apples and plums, which are also widely cultivated in the EU. The nematode only moves short distances (around 1 m) but may be spread with soil moving activities. Measures are available to inhibit entry via soil as such. Entry of the nematode with soil attached to plants for planting that are not regulated is possible. X. californicum does satisfy all the criteria that are within the remit of EFSA to assess to be regarded as a Union quarantine pest.