Despite significant medical advances in recent decades, asthma is still considered a challenge. This is the first candidate genes case-control study in Croatia that aims to clarify the genomic context of asthma in adults. The research hypothesis was that IL6R (1q21.3), RAD50 (5q31.1), STARD3 and ORMDL3 (17q12-21.1) gene polymorphisms were associated with an earlier disease onset, more severe asthma, a greater number of exacerbations and an allergic asthma phenotype. A total of 235 subjects with asthma, stage 1-4 (from mild to severe asthma) according to GINA criteria, took part in this research. It was found that the polymorphisms RS2897443 and RS2244012 (RAD50) are a risk factor for the development of nasal polyposis, RS1877031 (STARD3) is a risk factor for the onset of asthma and the development of nasal polyposis in children, but has a protective effect on the presence of asthma and the onset of the disease in adults and the occurrence of T2 allergic and eosinophilic phenotype. RS3744246 of the ORMDL3 gene carries an increased risk for the presence of asthma in adults, although it conffers a better controlled variant, while for the SNP of the IL6R gene, RS4129267, the only associations were found at the level of individual genotypes for the presence of asthma in adults and high values of blood eosinophilia and FeNO. In conclusion, asthma is a complex disease and here it has been proven that the knowledge about the genetic basis of pathophysiological processes in asthma obtained