Given the few studies highlighting the existence of an oil-price effect on agricultural commodity prices in the last decade, we sought to demonstrate the role of first-generation biofuel production in such a relationship. Relying on a smooth transition cointegration approach, we show that biofuel development has led to an increase in the long-term price effect of oil on agricultural commodity prices. Thus, the increasing production of biofuels contributes to the price rise of agricultural commodities. This result underlines the importance of accelerating second-generation biofuel production to replace first-generation biofuels.