This study utilizes the search volume for key terms on Google as a direct and timely proxy for investor attention in order to examine how attention impacts commodity futures prices, We provide significant evidence for attention's influence on 13 commodity futures and the interaction between attention and returns, even after controlling for important macroeconomic variables. We also examine the impact of investor attention on market efficiency. Results show that rising attention, on one hand, increases information efficiency and attenuates arbitrage opportunities, whereas, on the other hand, decreases market efficiency by facilitating herd behavior.