Alfalfa (Medicago sativa L.) production with cultivars susceptible to verticillium wilt (VW) (caused by Verticillium albo-atrum Reinke & Berthier) or those poorly adapted to the region causes significant losses in forage productivity in western Canada. This study estimated the economic benefits that could be obtained by growing VW-resistant and adapted cultivars in this region, The analysis used irrigated forage yield data from a 7-yr trial conducted near Lethbridge, AB. The yearly benefit of high resistance to VW over moderately high resistance was $21 ha(-1) and over low resistance was $44 ha(-1), The potential yearly benefits to producers in western Canada from the development and adoption of high VW-resistant cultivars were estimated at $2.2 million. The local benefits of growing adapted cultivars on irrigated land were $22 ha(-1) yr(-1). The regional benefits to western Canada from using adapted cultivars were $26.6 million yr(-1). The greater potential benefit from growing adapted cultivars was attributed to benefits applied to all areas of western Canada, whereas benefits from VW applied to areas infested with VW.