Leafy spurge (Euphorbia esula L.), a widely established exotic, noxious, perennial weed, is a major threat to the viability of commercial grazing and 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. Considering the wide geographic variation of leafy spurge infestations, the range of herbicide control alternatives, and the long-term consequences this weed creates, a need exists to assess the economics of herbicide control. A deterministic, bioeconomic model was developed to evaluate the economic viability of current herbicide control strategies for leafy spurge. Only under liberal assumptions and optimistic projections does broadcast herbicide treatment result in positive net returns for most grazing situations in the Upper Great Plains. However, herbicides usually result in less loss over the long-run than does no control.