Dermatological/cosmetic compositions suited for preventing or treating cell differentiation and/or proliferation and/or keratinization disorders, including preventing or treating common acne, comprise, in a physiologically acceptable medium, (i) at least one dispersed retinoid, (ii) dispersed benzoyl peroxide, in free or encapsulated form, and (iii) at least one pH-independent gelling agent, said dermatological/cosmetic composition having physical stability without loss of viscosity over time at a temperature ranging from 4.degree. C. to 40.degree. C., said dermatological/cosmetic composition having a stable flow threshold over time as measured by viscosity measurements for rheograms which measure a shear stress .tau. for a given rate gradient .gamma. and which measure a rate gradient .gamma. for a given shear stress .tau., the yield value (.tau.0) being extrapolated visually or by calculation.