Asthma is a complex disease of the immune system, characterized by chronic airway inflammation, narrowing of the airways and chest tightness. Permanent changes in airway structure can occur. The genetic background of asthma is extremely complicated and plays an important role in asthma development risk. The goal of this study was the construction of a database of genes, associated with asthma, the analysis of the database with bioinformatics tools and determining a candidate gene for further analysis in the laboratory. We collected 244 genes, analyzed their genomic locations and involvement in biological pathways with bioinformatics tools. Several critical regions were found, regions on the genome, where asthma associated genes are less than 1 Mbp apart. For further analyses, CSF2, an important inflammation mediator, was chosen. CSF2 lies in one of the critical regions and is involved in several important biological pathways. We investigated the presence of rs25882 polymorphism and the expression of CSF2 in a population of Slovenian patients. We found that the C allele increases the chances of nonatopic asthma, while the difference between expression of CSF2 in asthmatic and healthy patients was not shown to be statistically significant. Our study showed it is possible to obtain candidate genes for laboratory verification using bioinformatics tools. Further studies could use a similar approach, to search for new candidate genes, potentially leading to new approaches for the prevention of asthma development or treatment for the disease.