The CoR commissions are thematic commissions carrying out the legislative work of the Committee, which covers a broad range of areas that concern local and regional authorities.

The first plenary session ( 9-10/03/1994) establishes eight commissions, four sub-commissions and a commission for institutional affairs to prepare the CoR‘s opinions:
• Commission 1: Regional Development, Economic Development, Local and Regional Finances
• Subcommission 1: Local and regional finances
• Commission 2: Spatial planning, Agriculture, Hunting, Fisheries, Forestry, Marine environment and Upland Areas
• Subcommission 2: Tourism and Rural Areas
• Commission 3: Transport and Communications Network
• Subcommission 3: Telecommunications
• Commission 4: Urban Policies
• Commission 5: Land-use planning, Environment and Energy
• Commission 6: Education and Training
• Commission 7: Citizen‘s Europe, Research, culture, youth and consumers
• Subcommission 7: Youth and Sport
• Commission 8: Economic and Social Cohesion, Social Policy and Public Health.

Then in 1998, the consultative work was reorganized around eight permanent commissions.

In 2002, a third re-organisation of the commissions structures the CoR's work by means of six new commissions, replacing the previous eight ones:
CIVEX: citizenship, governance, institutional and external affairs
COTER: territorial cohesion policy;
ECON: economic policy;
ENVE: environment, climate change and energy;
NAT: natural resources and agriculture;
SEDEC: social policy, employment, education, culture and research.
And to assist the CoR Bureau, a special Commission for Financial and Administrative Affairs (CFAA) is established.

The commissions prepare draft opinions and hold conferences and seminars focused on their areas of competence. Each commission has approximately 100 members (each member can be part of two commissions) and is supported by a secretariat within the administration.