Electron microscopic study of conjunctiva in two cases of Sjögren's syndrome showed decrease in height and number of microvilli and lack of branching. Following immunosuppressive treatment, an increase in height, number and branching of conjunctival microvilli was observed. Notwithstanding the lack of influence on tear secretion, immunosuppressive drugs are of benefit in the treatment of ocular manifestations of Sjögren's syndrome. The increase in number, height and branching of microvilli enlarge the surface of the conjunctiva and thus improve the efficacy of artificial tears.