Between September 2007 and February 2010, the occurrence of symptomatic deep venous thrombosis (DVT) was investigated in a cohort of 79 consecutive patients. A case-control study inclu ded 71 healthy controls matched with cases for sex and age. The prevalence of factor V G1691A mutation genotype was analyzed. Eighteen cases (22.79%; 95% confidence interval (CI) 13.53% to 32.03%) and four controls (5.63%; 95% CI 0.27% to 10.99%) were heterozygous carriers of FV Leiden (p= 0.025). The odds ratio for DVT was 4.94 (95% CI 1.58 to 15.42) and the relative risk 4.04 (95% CI 1.44-11.38) compared with FV 1691G carriers. Four cases were homozygous carriers of FV Leiden, giving a prevalence of 5.06% (95% CI 0.23 to 9.89%) and no controls, therefore OR and RR calculation was based on the prevalence of homozygotes in the general Caucasian population. The OR for DVT was 47.28 (95% CI 0.04 - 52167.3) and the RR 45.57 (95% CI 0.04 to 49540.77; p=0.025) compared with FV 1691 G carriers. Our study confirms that factor V Leiden carriers in Vojvodina, as in similar studies previously carried out in other populations, have an increased risk of developing DVT. The evaluated risk of DVT in heterozygous carriers of the mutation is four- to five-fold higher, whereas for homozygous carriers it is 45- to 48-fold higher than in non-carriers. These results confirm that patients with DVT and their relatives should undergo screening for FV Leiden mutation. U periodu od septembra 2007 do februara 2010. ispitana je pojava duboke venske tromboze u kohorti od 79 pacijenata. Prospektivna studija je obuhvatila kontrolnu grupu koja se po odnosu polova i starosti poklapa sa grupom pacijenata. Analizirano je prisustvo mutacije faktor V G1691A u grupi obolelih i kontrolnoj grupi. Osamnaest obolelih (22,79%; 95% interval poverenja (CI) 13,53% do 32,03%) i četiri kontrole (5,63%; 95% CI 0,27-10,99%) bili su nosioci FV Leiden mutacije u heterozigotnom stanju (p = 0,025). Odnos verovatnoća (OR) za nastanak DVT iznosio je 4,94 (95% CI 1,58-15,42) a relativni rizik (RR) 4,04 (95% CI 1,44-11,38) u poređenju sa nosiocima neizmenjenog gena. Četiri obolela bili su nosioci FV Leiden mutacije u heterozigotnom stanju a nijedna zdrava osoba i stoga su OR i RR računati na osnovu opšte učestalosti homozigota u beloj populaciji. OR za DVT bio je 47,28 (95% CI 0,04-52167,3) a RR 45,57 (95% CI 0,04-49540,77; p=0,025) Naša studija potvrđuje da nosioci FV Leiden mutacije u Vojvodini, kao u studijama rađenim na drugim populacijama, imaju povećan rizik za nastanak DVT. Procenjen rizik od nastanka DVT za nosioce faktor V Leiden mutacije u heterozigotnom stanju je četiri do pet puta veći a za homozigotne nosioce čak oko 45 do 48 puta veći u odnosu na nosioce neizmenjenog gena za FV. Ovi rezultati potvrđuju da kod pacijenata sa DVT, kao i njihovih rođaka, treba ispitati prisustvo FV Leiden mutacije.