The objectives of this study were to determine genotypic and allelic frequencies of macrophage migration inhibitory factor (MIF) gene -173 G/C polymorphism in patients with juvenile rheumatoid arthritis (JRA) and to evaluate the association of the MIF -173 C allele with the outcome of JRA. Genomic DNA was collected from 67 JRA patients and 153 healthy individuals. To evaluate the association of the MIF -173 polymorphism with the outcome, we analyzed the data concerning the treatment regimen, duration of glucocorticoid treatment, score on the childhood health assessment questionnaire (C-HAQ) and the number of joints with active arthritis. Nonsignificant differences were observed between the study and control groups in the distribution of genotype and allele frequencies of the MIF gene -173 G/C polymorphism. In JRA patients, carrying a MIF -173 C allele, the number of disease modifying antirheumatic drugs required for the treatment was more, the duration of glucocorticoid treatment was significantly longer, and at the last visits the C-HAQ scores and the number of joints with active arthritis were significantly higher. MIF gene -173 C allele frequency did not differ between the controls and JRA patients. MIF -173 C allele did not confer increased susceptibility to JRA in our study group. Carriage of the MIF -173 C allele was found to be a strong predictor of poor outcome in all types of JRA.