Nanoscale, pyrogenically produced zinc oxide having a BET surface area of 10 to 200 m.sup.2/g, which is in the form of aggregates of anisotropic primary particles and whereby the aggregates display an average diameter of 50 to 300 nm. It is obtained from zinc powder, which is converted to zinc oxide powder in the four successive reaction zones, evaporation zone, nucleation zone, oxidation zone and quench zone. It can be used in sunscreen formulations.