The aim of the present study was to investigate whether any correlation between PV and MICA polymorphism exist in our sample of patients with psoriasis vulgaris (PV). Seventy-seven Croatian patients with PV were studied, they were divided into two groups ; 53 patients with type I psoriasis and 24 patients with type II of disease. The number of triplet repeats in the TM region of MICA gene was analysed by PCR-STR analysis in an automated DNA sequencer (ALFexpress). Among patients with PV the most frequent MICA allele was MICA A5.1 (36.4%) as well as in controls (27.6%). Analysis of two subgroups of patients did not show any difference in distribution of this allele. Comparisons for the rest of MICA alleles showed significant differences for two MICA alleles. MICA-A4 was significantly decreased among all patients (9.1% vs 18.2%, p=0.0098 ; pcorr=0.049) while among patients with PV type I decrease was statistically significant only before correction (8.5% vs 18.2, p=0.012 ; pcorr=0.061). The frequency of MICA-A9 allele was significantly increased after correction among all patients with psoriasis (31.2% vs 17.9%, p=0.001, pcor=0.005), as well as among patients with psoriasis type I (31.1% vs 17.9%, p=0.003 ; pcor=0.015). Stratification analysis showed that higher frequency of MICA-A9 allele is due to the linkage disequlibrium with B57 antigen. Extended haplotype associated with psoriasis type I in the Croatian population looks as follows: Cw*0602, -B57, -MICA-A9, -DRB1*0701, -DQA1*0201, -DQB1*02.