The threat to human health and vegetation by ozone is still an important topic in politics, science and the public in Germany. A workshop organized by the German Environment Agency (Umweltbundesamt) and the Institute for Advanced Sustainability Studies (IASS Potsdam) addressed this issue. Experts discussed the current state of knowledge on processes relevant for ozone, the need for improvement concerning models and measurements, the quality of the current emission inventories, and the contribution of regional ozone production to overall pollution. In addition, general recommendations for reducing emissions of ozone precursors in Germany were discussed and knowledge gaps and further research needs identified.