In a survey, primarily from the rhizosphere of hardwood trees growing on sandy stream banks, for longidorids, 828 soil samples were collected from 37 Arkansas counties in 1999-2001. One hundred twenty-seven populations of Xiphinema were recovered from 452 of the 828 soil samples (54.6%), including 71 populations of X. americanum sensu lato, 33 populations of X. bakeri, 23 populations of X. chambersi and one population of X. krugi. The morphological and morphometric characteristics of these Arkansas species are presented. Morphological and morphometric characteristics are also given for two populations of X. krugi from Hawaii and North Carolina.