AbstractMultiple sclerosis (MS) is a chronic, progressive disease of the central nervous system (CNS) characterized by consistent myelin injury. Antibody‐mediated death of oligodendrocytes is a pathological feature in a subset of MS patients and may be of relevance to disease pathogenesis. In myasthenia gravis (MG), acetylcholine receptors (AChR) situated at the neuromuscular endplate are destroyed by autoreactive antibodies. B‐cell activating factor of the tumour necrosis factor (TNF) superfamily (BAFF) is essential for B‐cell survival. Using flow cytometry, we evaluated the expression of three BAFF‐binding receptors, namely, BAFF‐receptor (BAFF‐R), B‐cell maturation antigen (BCMA), and transmembrane activator and calcium modulating and cyclophilin ligand interactor (TACI) in peripheral‐blood lymphocytes. Nearly all CD19+ B cells and CD19+CD27+ memory B cells expressed BAFF‐R. The intensity of BAFF‐R expression was not statistically different in MS or MG compared with healthy controls. Very few T cells expressed BAFF‐R. BCMA expression was strictly limited to B cells. Although both B and T cells expressed TACI, levels were much higher on B cells compared with levels on T cells. The percentages of B and T cells expressing BCMA and TACI did not differ significantly in MS or MG versus controls. We conclude that the expression of BAFF‐binding receptors is not appreciably altered in MS or MG.