Recently a premix of tolpyralate and bromoxynil was registered in the USA and Canada by Corteva Agriscience for weed control in cereals. Limited information exists on weed control efficacy and crop safety with this new herbicide pre-mixture. Greenhouse trials were conducted for two years to test the efficacy of tolpyralate and bromoxynil combinations on 14 broadleaf and 4 grass weeds and crop safety in wheat and barley. Four combinations of tolpyralate and bromoxynil at 1:10 ratio (3.75 + 37.5, 7.5+ 75, 11.25 + 112.5, and 15 + 150 g ai ha-1) as a tank-mix and premix were tested. Stand-alone treatments of tolpyralate and bromoxynil were also included in this study. The lowest tested rate of tolpyralate (3.75 g ha-1) provided 10 to 98% and 27 to 77% control of broadleaf and grass weeds, respectively. Bromoxynil at the lowest tested rate (37.5 g ha-1) provided 16 to 80% and 0 to 30% control of broadleaf and grass weeds, respectively. Tank-mixing these two herbicides at the same rates had improved broadleaf (60 to 100%) and grass (45 to 94%) weed control. The minimum recommended field use rate of tolpyralate +bromoxynil (15 + 150 g ha-1) controlled all the broadleaf weeds >95%. This combination also controlled green foxtail, barnyardgrass and large crabgrass >90%. Additive or synergistic effect between the two herbicides was observed on several broadleaf and grass weed species. Among all the tested weeds, greater synergistic effect was observed on kochia, chickweed, wild mustard, corn poppy, barnyardgrass, green foxtail, and fall panicum. The premix of the two herbicides provided similar broadleaf control, but better grass weed control compared to the tank-mix combinations. Premix was safe on wheat and barley.