The experimental sulfonylurea herbicide ASC-67040 was evaluated preemergence (PRE) and postemergence (POST) at 25 to 100 g ai/ha and PRE at 50 g/ha followed by ASC-67040 POST at 50 g/ha for broadleaf weed control in potato and tomato. In Virginia, ASC-67040 POST at 50 and 100 g/ha gave 70 to 98% control of common lambsquarters, common ragweed, and jimsonweed with slight (0 to 6%) ‘Superior’ potato and moderate (0 to 23%) ‘Agriset’ tomato injury. This crop injury was present primarily as chlorosis in terminal growth and disappeared by 3 wk after treatment (WAT). Potato tuber and tomato fruit yields were high in ASC-67040-treated plots. In North Carolina, ASC-67040 PRE and POST at 50 and 100 g/ha controlled 10 species of annual broadleaf weeds and grasses, and at 25 g/ha ASC-67040 gave greater than 90% control of most species. ASC-67040 injured ‘Fontenot’ potato more than Superior and caused 10 to 13% injury to ‘Mountain Spring’ tomato but did not injure ‘Mountain Pride’ tomato. Mountain Spring tomato recovered rapidly and produced high yields. In the greenhouse, yellow nutsedge control by ASC-67040 POST at 25 to 100 g/ha was 59 to 86% 3 WAT and yellow nutsedge height, dry weight, and regrowth dry weight were reduced by all rates. Lower rates of ASC-67040 might control weeds and cause less injury to potato and tomato.