Koelnmesse GmbH stands for the group's core businesses operations: the regular organization of about 40 trade fairs and specialist exhibitions. These include the leading global trade fairs for 25 different sectors. The trade fair program focuses on Koelnmesse's main areas of expertise, which are bundled in the following business units: Communication & New Media; House, Garden & Leisure; Art & Culture; Food; Furniture & Interior Design; Fashion; and Health, Environment & Facilities. International trade fairs at locations outside the Cologne exhibition grounds are organized by Koelnmesse International GmbH, which also manages the company's subsidiaries abroad. With the help of the Cologne company's expert knowledge of specific sectors, Koelnmesse International GmbH supplements the leading global trade fairs taking place in Cologne by opening up additional markets all over the world and launching activities in selected target regions and local markets. Koelnmesse Ausstellungen GmbH markets available hall space in Cologne that is used for guest events by associations, purchasing cooperatives, and national and international trade fair organizers who have no exhibition grounds of their own. It also acts as the independent organizer of events oriented toward the general public that are held in Cologne and other locations in Germany. Finally, Koelnmesse Service GmbH provides exhibitors and visitors with a comprehensive range of services from a single source. It offers a full-service package that ranges from travel arrangements and accommodation to the planning and organization of trade fair stands and supporting events, all the way to professional advertising and media support.

The events regularly held by the Koelnmesse Group at different intervals bring together the products presented by 42,000 exhibiting companies from 120 countries with the demand represented by two million visitors from 175 countries. All of these trade fairs put together occupy some 4.2 million square meters of exhibition space. The Cologne exhibition grounds, which cover 286,000 square meters of exhibition space, are the fourth-largest in the world.