The GRAPPA Institute hosted on April 12 and 13 an ‘Amsterdam-Paris-Stockholm’ workshop on Dark Matter: an informal meeting with Astroparticle groups in Paris and Stockholm. The participants included: Chiara Arina (RWTH Aachen), Alexander Belikov (IAP Paris), Lars Bergstrom (OKC Stockholm), Gianfranco Bertone (GRAPPA Amsterdam), Maria Cabrera (U. Autonoma Madrid, soon GRAPPA Amsterdam), Marco Cirelli (CERN/CEA Saclay), Patrick Decowski (GRAPPA Amsterdam), Joakim Edsjo (OKC Stockholm), Silvia Galli (IAP Paris), Fabio Iocco (OKC Stockholm), Paul de Jong (NIKHEF Amsterdam), Joe Silk (IAP Paris), Tracy Slatyer (IAS Princeton).