- Academic Radiotherapy Unit
- ACCESS EV
- ACCESS (GERMANY)
- ACCESS Linnaeus Centre [Sweden]
- Acxys
- Advanced CERamics Deposition
- Advanced Materials Lab.
- Advanced Photon Source [ANL]
- A.F. Ioffe Physical-Technical Institute
- Agronomy for Sustainable Development
- Alcan CRV
- ALCAN Ctre Recherches
- AlCAN Rio TINTO
- Alcatel CIT
- Alfa Laval AB
- Ames Laboratory [Ames, USA]
- Ampère
- Analyse, Géométrie et Modélisation
- Angström Laboratory
- Aperam Alloys Imphy
- APERAM ISBERGUES
- Apollon Solar
- Applications des ultrasons à la thérapie
- Applied Physics
- Applied Physics Laboratory [Beirut]
- ARC Centre of Excellence for Design in Light Metals
- ARC CoE Design Light. Met.
- ArcelorMittal Maizières Research SA
- ArcelorMittal Research Liège
- ArcelorMittal Stainless Steel Europe
- AREVA
- AREVA NC
- AREVA NP
- Argelander Institute for Astronomy
- Arrhenius Laboratory
- Artificial Intelligence Research Center [Tokyo]
- ASCOMETAL CREAS
- Association AstroQueyras
- Association des Utilisateurs de Détecteurs Electroniques
- Association EURATOM-CEA
- Association EURATOM-ÖAW
- Association of Computer Electronics and Electrical Engineers (ACEEE)
- ASTEK Rhône Alpes
- ASTRIUM
- Astronomical Institute of Charles University
- Astronomical Observatory [Poznan]
- Astronomy Centre
- AstroParticule et Cosmologie
- Astrophysique Interprétation Modélisation
- Atmostat
- AUXITROL SA
- A. V. Shubnikov Institute of Crystallography