The primary aim was to determine frequencies of mutations related to risk of venous thrombosis in healthy Caucasians in Central Bohemia. In a cohort of 1527 healthy individuals the frequency of risk alleles for the mutations FV Leiden and FII 20210G>A was 4.5% and 1.3%, respectively. Frequency of 4G PAI-1 allele was 55.5%. Genotype frequencies were: GG 91.03%, GA 8.91%, and AA 0.07% for FV Leiden; GG 97.45%, GA 2.49%, and AA 0.07% for FII 20210G>A; 4G/4G 30.26%, 4G/5G 50.56%, and 5G/5G 19.19% for PAI-1. Frequency of the risk allele A in polymorphism SERPINC1 (IVS +141G >A) was 11.3%, and frequencies of genotypes were as follows: GG 78.36%, GA 20.66%, and AA 0.98%. Frequency of the risk allele T for polymorphism GP6 13254T>C was 87.7%, and frequencies of genotypes were as follows: TT 77.14%, TC 21.15%, and CC 1.70%. Frequency of the risk allele A in polymorphism CYP4V2 (Lys259Gln) was 65.2%, and frequencies of genotypes were: CC 12.25%, CA 45.12 %, and AA 42.63%. All observed genotypes and alleles frequencies were without gender differences. Their occurrences confirm a relatively high prevalence of hereditary thrombophilia predisposition in the Czech Republic.