Activation of transcription factor NF-kappa B in the central nervous system (CNS) has been linked to autoimmune demyelinating disease; however, it remains unclear whether its function is protective or pathogenic. Here we show that CNS-restricted ablation of 'upstream' NF-kappa B activators NEMO or IKK2 but not IKK1 ameliorated disease pathology in a mouse model of multiple sclerosis, suggesting that 'canonical' NF-kappa B activation in cells of the CNS has a mainly pathogenic function in autoimmune demyelinating disease. NF-kappa B inhibition prevented the expression of proinflammatory cytokines, chemokines and the adhesion molecule VCAM-1 from CNS-resident cells. Thus, NF-kappa B-dependent gene expression in non-microglial cells of the CNS provides a permissive proinflammatory milieu that is critical for CNS inflammation and tissue damage in autoimmune demyelinating disease.