This report summarizes the pesticide assessment for corn and soybeans in the Northern Plains. Without insecticides, corn rootworm larvae and other soil insects would cause substantial corn yield losses. The loss of seed treatments would result in yield losses to both corn and soybeans. Among the herbicides, the loss of thiocarbamates would cause the greatest corn yield losses, while either dinitroanilines or triazines would cause the greatest soybean yield losses. This report includes pest rankings, estimates of acreages treated with pesticides or other pest management practices, and estimates of pest losses with and without pesticide use for insects, diseases, nematodes, and weeds