Glyphosate-resistant horseweed (Conyza canadensis) in Arkansas was first confirmed in Mississippi County in 2003, but has since spread to the southern-most counties in the Mississippi Delta. Glyphosate alone has been routinely applied in the spring for burndown weed control prior to planting cotton. In the absence of spring tillage, effective herbicide programs are needed for control of glyphosate-resistant horseweed. From 2004 through 2006, 45 trials were conducted to determine the most effective programs for control of glyphosate-resistant horseweed. Valor (flumioxazin) and Envoke (trifloxysulfuron) applied in the fall provided effective horseweed control throughout the winter months, but by early spring, control was erratic among locations and sometimes less than acceptable. Suprend (trifloxysulfuron + prometryn) applied in the fall provided consistent and effective (>90%) horseweed control through cotton planting; however, injury to cotton in the form of stunting was sometimes observed. Clarity (dicamba) applied 3 to 4 weeks prior to planting effectively controlled horseweed through crop planting. Recommendations for controlling glyphosate-resistant horseweed developed from these trials are to apply Clarity at 3 weeks prior to planting. If Clarity does not provide sufficient residual control to prevent horseweed emergence prior to planting, Gramoxone Inteon (paraquat) or Ignite (glufosinate) can be applied to remove horseweed seedlings. Direx (diuron), Caparol (prometryn), or Cotoran (fluometuron) provide residual horseweed control and should be applied at planting to maximize the length of in-crop control. If horseweed seedlings are a problem at planting, consider in subsequent years mixing a residual herbicide with Clarity at burndown, realizing that the length of in-crop residual control will be reduced. Envoke can be applied over-the-top of cotton to control horseweed seedlings that emerge once the residual herbicides have dissipated. Research is still needed to determine the influence of rainfall and soil type on the length of residual horseweed control from Clarity.