Abstract A carboxylic acid, an aldehyde, and an isonitrile were combined in a single step (Passerini reaction) under mechanochemical activation to produce several α‐acyloxycarboxamide derivatives in high to excellent yields within 15 min of milling. Mechanochemistry, when combined with the diversity provided by multicomponent reactions, enables the efficient synthesis of the target compounds, with great atom economy, shorter reaction times, and experimental simplicity. The method allows for the rapid production of a vast library of complex compounds from a limited number of substrates.