Experimental autoimmune encephalomyelitis (EAE) in the rat is an acute paralytic disease from which most animals spontaneously recover. The disease can be induced in susceptible inbred Lewis and DA rats with myelin basic protein (MBP), or encephalitogenic MBP peptides administered in complete Freund's adjuvant (CFA). The disease can be adoptively transferred to syngeneic recipients with primed T cells that have been reactivated in vitro with antigen. EAE is mediated by CD4+ Th1 cells that secrete proinflammatory cytokines, and spontaneous remission is associated with CD4+ T cells that secrete transforming growth factor-beta (TGF-beta). Studies of EAE in susceptible rats have provided many important insights into the interactions of T cells and accessory cells that culminate in the induction of the autoimmune response.