In 2008, the nominal GDP of the citystate Berlin experienced a growth rate of 1.6% (1.3% in Germany) and totaled €83.0 ($108) billion. After Germany's reunification, significant de-industrialization changed Berlin's economy which is today dominated by the service sector. The unemployment rate steadily decreased and reached a 13 year-low with 13.3% in September 2008 (German average: 7.4%/September/2008).

Among the Forbes Global 2000 and the 30 German DAX companies, Siemens and Deutsche Bahn control headquarters in Berlin. A multitude of German and international companies established secondary departments or service offices in the city. Among the 20 largest employers in Berlin are the railway company Deutsche Bahn, the hospital company Charité, the local public transport company BVG, the service provider Dussmann and the Piepenbrock Group. Daimler manufactures cars, and BMW builds motorcycles in Berlin. Bayer Schering Pharma and Berlin Chemie are major pharmaceutical companies headquartered in the city. The second most important German airline Air Berlin and the rail company Deutsche Bahn are headquartered in Berlin. In Germany, Universal Music and Sony Music are headquartered in Berlin as well.

Fast-growing sectors are communications, life sciences, mobility and services with information and communication technologies, media and music, advertising and design, biotechnology and environmental services, transportation and medical engineering.

The Science and Business Park of Berlin-Adlershof is among the 15 largest technology parks worldwide. Research and development have established economic significance, and the Berlin Brandenburg region ranks among the top three innovative regions in the EU. Berlin is among the top three convention cities in the world and is home to Europe's biggest convention center in the form of the Internationales Congress Centrum (ICC). It contributes to the rapidly increasing tourism sector encompassing 659 hotels with 97,400 beds and numbered 17.8 million overnight stays and 7.9 million hotel guests in 2008. Berlin has established itself as the third most-visited city destination in the European Union.