Nanocosmetics are personal care products containing nanocarriers or nanoparticles. Nanocarriers have been used in sunscreens, moisturizers, perfumes, and anti-aging and hair products. These carriers increase formulation efficacy and promote controlled release of active ingredients. Polymeric nanocarriers or lipid nanocarriers containing sunscreens have enhanced ultraviolet protection. In addition, these nanocarriers protect unstable ingredients from degrading ultraviolet radiations. Furthermore, nanocarriers also impart moisturizing effect due to their reduced particle size. This chapter describes issues related to nanocarrier-based cosmetics production, characterization, and biological evaluation.