The purpose of this study was to estimate the impact of the major factors affecting the export demand for U.S. walnuts in Asia and the European Union (E.U.), which together import about 75 percent of U.S. walnut exports. The primary objective pertained to the impacts of federal promotion programs on the foreign demand for U.S. walnuts. The marginal return per dollar to decreasing promotion expenditures for walnuts was $6.14 for Asia, reflecting prudent utilization of promotion expenditures as the Asian market for U.S. walnuts approaches maturity. The European Union appears to be a mature market for U.S. walnut exports with no detectable responsiveness to promotion expenditures.