A cosmetic composition including a yeast hydrolysate and to the use thereof in cosmetics, for promoting moisturization of the skin and/or protecting human skin against drying out and/or improving the barrier function and/or for an anti-ageing effect. The yeast hydrolysate is obtained by a process that includes solubilization of the yeast in water, enzymatic hydrolysis, separation of the soluble and insoluble phase and recovery of the soluble phase, enzymatic inactivation, and optionally concentration and sterilizing filtration.