The Idaho–Eastern Oregon onion industry operates in a market environment characterized by a high level of onion price and supply volatility. Years of relatively high onion prices are often followed by years of very low prices which do not allow onion growers to recover their onion production costs. This feature of the industry adversely affects the profi tability of onion growers and the economic performance of their industry. This study conducts an analysis of alternative market scenarios for the Idaho–Eastern Oregon onion industry in the light of possible implementation of the onion supply management strategy. The results presented in this paper can be used to make a decision on the onion area planted and to predict how changes in the onion supply level would affect the level of onion price in the analyzed industry.