The organic anion transporting polypeptide 1B1 (encoded by SLCO1B1 gene) is involved in the active cellular influx of diverse endogenous compounds and several drugs, such as HMG-CoA reductase inhibitors (statins). Two common polymorphisms c.388A>G and c.521T>C in SLCO1B1 alter transport activity of this transporter and play an important role in the pharmaceutical response to many drugs. The aim of our study was to investigate frequencies of common SNPs in SLCO1B1 gene in Western Slavic population. We determined frequencies of two common polymorphisms c.388A>G and c.521T>C in the SLCO1B1 gene in the control group consisting of 83 healthy volunteers from Slavic population by PCR-RFLP and allele-specific Real-Time PCR. Presented results were statistically evaluated and compared with known data of different ethnic groups. The allelic frequencies of SLCO1B1 SNPs were 37% for minor allele c.388G and 23% for c.521C. SLCO1B1 SNPs c.388A>G and c.521T>C were relatively frequent in Slovak population and allelic frequencies generally correspond with data published for other population of Caucasian origin. We also determined that 19% of individuals with Gilbert syndrome (ATA7/7TAA) carried the genotype c.388GG of the SLCO1B1 gene. According to our findings, analyzed SNPs in the SLCO1B1 gene are frequent enough for consideration of their screening in patients indicated for treatment with drugs involved in OATP1B1 mediated transport. Detection of polymorphisms in SLCO1B1 is beneficial for avoiding adverse drug reaction.