In the present study, short tandem repeats (STR) polymorphism within the first intron of IFN-gamma gene in connection with HLA-DRB1*03 specificities was analysed in 43 sarcoidosis patients, 14 of which presented with Löfgren's syndrome (LS). Four out of 5 known IFN-gamma alleles with 12-15 CA repeats, respectively were detected in sarcoidosis patients. IFN-gamma 3,3 homozygosity was found to constitute a risk factor associating with LS manifestation (0.50 versus 0.19, OD = 4.18, P = 0.014). As expected, DRB1*03 prevailed in LS cases (9/14 versus 7/29, P = 0.014 LS versus non-LS cases and 9/14 versus 35/162, OD = 6.20, P = 0.001, LS patients versus controls). However, we also showed the presence of a combined association between DRB1*03 and IFN-gamma 3,3 in sarcoidosis (P = 0.017) and LS patients (P = 0.001).