According to the European Cosmetics Directive, succeeded by Regulation (EC) No 1223/200, a “cosmetic product”’ is defined as “any substance or mixture intended to be placed in contact with the external parts of the human body (epidermis, hair system, nails, lips and external genital organs) or with the teeth and the mucous membranes of the oral cavity with a view exclusively or mainly to cleaning them, perfuming them, changing their appearance, protecting them, keeping them in good condition or correcting body odours”. A cosmetic product made available on the market shall be safe for human health when used under normal or reasonably foreseeable conditions of use. The European Cosmetics Directive has significantly influenced not only the European, but the global cosmetics industry by establishing rigorous safety and improving efficacy documentation standards. This chapter describes the European regulations regarding safety and efficacy assessment of cosmetics aund examines the Directive’s role in international harmonization, highlighting how it has set a benchmark for cosmetic product regulation worldwide.