In response to the introduction and rapid spread of soybean aphid as a major new invasive pest of soybean in North America, farmers who attended winter crop meetings in four states in North Central US were surveyed about their treatment of and knowledge about soybean aphids for crop years 2004, 2005, and 2006. Thirteen percent, 84%, and 35% of the farmers indicated they had treated for soybean aphid in 2004, 2005, and 2006, respectively. The average of the soybean acreage treated in each year was 50%, 87%, and 81%, respectively. Overall, the farmers showed a good understanding of soybean aphids and their impact on soybeans. Over 80% knew soybean aphids could repopulate and cause yield damage after an insecticide treatment. Seventy-five percent knew aphids damaged soybeans by sucking sap. Almost 80% said the frequency with which aphids should be treated for profitable control depends on aphid counts, weather conditions, and plant stage. On average, just under 70% considered an average of 250 aphids per plant to be the lowest density for profitable insecticide spraying. Scouting reports were selected by 84 to 94% of the farmers as very important information for the treatment decision; plant growth stage was the second most frequent selection.