A case-report of a patient suffering from two immunopathological diseases – primary idiopathic polymyositis and multiple sclerosis – is presented. The diagnostic criteria according to Bohan and Peter as well as those according to Tanimoto et al. were fulfilled for primary idiopathic polymyositis on the level of definite diagnosis. Multiple sclerosis met the diagnostic criteria according to McDonald et al. Generally, immunopathological disorders tend to reciprocal co-incidence, but that of primary idiopathic polymyositis and multiple sclerosis has not been reported in literature yet.

        Key words: polymyositis, multiple sclerosis