The objective of this study was to determine the effectiveness of tebuthiuron  {N- [5-(1,1-dimethylethyl)-1, 3,4- thiadiazol- 2- yl) -N,N' -dimethylurea} to treat brush-infested arid rangeland under field-scale conditions. A 130- ha tract in southern New Mexico dominated by creosotebush  [Larrea tridentata (Sesse & Moe. ex DC.) Coville #³ LARTR] was treated with pelleted tebuthiuron at 0.4 kg ai/ha. After the fourth season following treatment, control of creosotebush, honey mesquite (Prosopis glandulosa Torr. # PRCJG), and tarbush (Flourensia cernua DC. # FLOCE) was 87, 48, and 100%, respectively. Total shrub density was reduced from 4440 plants/ha to 570 plants/ha. Grass basal area increased from 1.1 to 3.4%. The treatment did not affect forbs greatly. Total herbaceous above-ground biomass production in the fourth season after treatment was 860 kg/ha compared to 140 kg/ha on an adjacent untreated area. Perennial grass production was nearly 11- fold greater on the treated area than on the untreated area.