OBJECTIVE The aim of this study was to determine ABO and RhD blood group distribution in nasal polyposis (NP) patients and whether there is a specific ABO or RhD blood phenotype associated with susceptibility to or protection with respect to development of NP. METHODS The study group comprised 126 consecutive patients with chronic rhinosinusitis and bilateral NP. The control group comprised 126 healthy blood donors. All participants were from the same geographical region. Distribution of ABO and RhD phenotypes in all participants was studied. RESULTS There were no significant differences between patients and controls in the distribution of the A (p=0.520), B (p=0.306), AB (p=0.673), O (p=0.894), and RhD (p=0.742) phenotypes. CONCLUSIONS According to the present results, the ABO and RhD blood group systems are not associated with development of NP.