This paper looks at the recent boom in agricultural commodity prices to see to what extent the changes these prices reflect are of a structural rather than short term nature. It concludes that they are essentially short term: a lagged supply response to the agricultural depression of 1970 and 1971; the coincidence of normal commodity cycles for several commodities; an unusual coincidence of adverse seasonal conditions in major producing areas, particularly the U.S.S.R.; and an unprecedented upswing in world economic activity. Nevertheless, there are a number of factors which suggest that, other than possibly in short term disequilibrium situations, agricultural commodity prices will not decline to previous levels: worldwide inflation; redirection in world agricultural support policies; and the energy crisis. Many of these factors win also influence prices of manufactured goods and hence the terms of trade. After considering the problems of world food supplies and continued growth in world population, the paper suggests that there is little evidence of a major structural change in the market for agricultural commodities. Rather, it points to a return to the previous situation where there is a slight tendency for the terms of trade to move against agriculture.