A process for digesting molybdenum oxide concentrates includes suspending a molybdenum-containing starting material in an aqueous solution so as to obtain a suspension. While stirring, an oxidizing agent and an alkali solution of at least one alkali metal are metered to the suspension so as to set a pH and produce a product having a molybdenum content of at least 98% of the molybdenum-containing starting material. The alkali metal is selected from the group consisting of Na, K and Li.