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Microphyllous desert scrub communities cover about 19.5x10(6)ha and are the most common and widely distributed vegetation in arid areas of Mexico. Larrea tridentata (DC) Coville, an evergreen creosote bush or chaparral that can survive in extreme drought conditions, due mainly to its allelopathic substances and secondary metabolites, is typically found as the dominant species in this community. The aim of this study was to evaluate the structure and diversity of a microphyllous scrub community dominated by L. tridentata in Northeastern Mexico. To determine the composition, diversity and structure of a community consisting of trees, shrubs and succulents, 10 circular sample sites, each of 500m(2), were established. Within each circular site, square-shaped sampling sites of 1.0m(2) were established in order to evaluate herbaceous vegetation. The plant species were idetified and the diameters of each individual crown measured. Margalef (D-Mg) and Shannon-Weiner (H) indices were calculated to determine the richness and diversity of species, respectively. Forty species, 33 genera and 12 families of vascular plants were registered. Families with the most species were Cactaceae (13), Fabaceae (8) and Asteraceae (5). The L. tridentata microphyllous scrub community has a high species richness compared to other xerophilous scrub communities in Northeastern Mexico. The distribution of species abundance was adjusted to the Pareto model, due to the abundance or rare species that characterizes stressful environments.