Interleukin-10 is a potent immunomodulatory cytokine with possible implications for the pathogenesis of multiple sclerosis. Increased IL10 mRNA expression is associated with stable disease. The interleukin 10 gene is highly polymorphic and certain haplotypes result in differential interleukin-10 expression. The presence of guanine instead of adenine at position -1082 in the IL10 promotor was shown to result in a higher IL10 production. We analysed this diallelic polymorphism in patients with multiple sclerosis but did not find any association between a certain -1082 IL10 genotype and susceptibility to or severity of multiple sclerosis.