The first commercial interest in Mexican oil was expressed during the imperial government of Maximilian and was a response to the global oil boom caused by the modern exploitation of U.S. crude. The purpose of this article is to explain this surge in interest in oil, analyze its principal manifestations and evaluate its scope and consequences. In particular, it distinguishes between pressures from abroad, the measures undertaken by Maximilian and their effects and the interests and expectations of domestic actors when faced with this new opportunity. It also evaluates the role the events of the mid-1860s in giving Mexican oil a commercial status.