Leafy spurge (Euphorbia esula L.), a widely established exotic, noxious, perennial weed, is a major threat to the viability of commercial grazing and to beneficial outputs of wildlands in the Upper Great Plains. Herbicide treatments are often recommended based upon measures of physical control rather than on economic criteria. A deterministic, bioeconomic model was developed to evaluate the economic viability of current herbicide control strategies for leafy spurge. Control viability is highly site specific but falls into three categories. First, broadcast herbicide treatment may result in positive net returns for some grazing situations, especially small infestations on highly productive land, in the Upper Great Plains. Second, treating the perimeter to prevent patch expansion is viable in some situations when treating the entire infestation is not viable. Finally, for well-established infestations on less-productive land the best alternative, from an individual landownerï¿½'s perspective, is to not treat leafy spurge with herbicide and bear the increasing productivity losses.