Chemokines form a relatively new family of chemotactic cytokines that seem to play a central role in the migration and activation of leukocytes in a wide variety of immune-mediated disorders. Specific therapy targeted against these proteins may well become an effective treatment in many of these disorders. The efficacy and safety of chemokine blockade is currently being investigated in clinical trials on patients with HIV infection, multiple sclerosis, rheumatoid arthritis and other chronic inflammatory disorders. The first results have been reported in patients with rheumatoid arthritis and these seem to confirm the potency of this treatment.