We used enterprise budgets, ordinary least squares regression, and data from the USDA Agricultural Marketing Service to estimate potential changes in costs and returns from use of a partially onion thrips (Thrips tabaci L. Thysanoptera) resistant-cultivar and action-based spray thresholds in onion (Allium cepa L.) producing regions of Idaho and Eastern Oregon. Results suggested the need for management strategies that could reduce the number of insecticide applications used to protect the crop from damage by onion thrips and Iris yellow spot while ensuring a high yield of onions grade in the largest size categories. Analysis indicated an effective cultivar could increase profits $641.10 to $1,013.63 per hectare compared with current marketable yields and management practices.