To provide a method for producing a calcium magnesium carboxylate, capable of omitting a drying process and capable of producing the calcium magnesium carboxylate in a wide calcium/magnesium(Ca/Mg) ratio.

This method for producing a calcium magnesium carboxylate comprises subjecting an organic carboxylic acid and water to a dry mixing or kneading treatment, while continuously or intermittently adding the organic carboxylic acid and the water to the calcium magnesium component to form continuous gaseous phases in spaces among the solid components. During the dry mixing or kneading treatment, the water is added in an amount of 0.1-1.0 mole per mole of the organic carboxylic acid, and the organic carboxylic acid and the water are added in a total amount of ≤20 pts.wt. per 100 pts.wt. of the calcium magnesium component.