Recent theoretical research deals with economic costs and benefits of cultural diversity related to immigration. However, empirical evidence regarding the impact of cultural diversity on economic performance is still scarce. This paper investigates the significance of cultural diversity of the workforce on innovation output for a cross-section of German regions. The findings indicate that cultural diversity indeed affects innovative activity. The results suggest that differences in knowledge and capabilities of workers from diverse cultural backgrounds enhance performance of regional R&D sectors. However, education levels are also important. Diversity among highly qualified employees has the strongest impact on innovation output.