Photostable cosmetic compositions comprising sunscreens, more particularly to cosmetic compositions comprising dibenzoylmethane sunscreens are provided. It is known that dibenzoylmethane and its derivatives are relatively sensitive to ultraviolet radiation and they decompose rapidly under the effect of sunlight. This decomposition is accelerated in the presence of UV-B sunscreens, especially p-methoxycinnamic acid and its derivatives. The present inventors have surprisingly found that cosmetic compositions comprising dibenzoylmethane or its derivative and p-methoxycinnamic acid or its derivative, can be stabilized by incorporating a combination of fatty alcohol ethoxylates and polyalkyleneglycol.