Background: Approximately 80 fungus species have been reported to be connected with respiratory allergy. Moreover, it is proven that four of them are the most common: Alternaria, Cladosporium, Aspergillus, and Penicillium. Despite of this, sensitization rates to these mould aeroallergens in children with asthma and allergic rhinitis are underreported. Objectives: The aim of this study was to investigate the sensitization rates to mould allergens and to establish the correlation between them and sensitization to the other most common aeroallergens. Materials and methods: The study population consisted of 205 patients (126 boys and 79 girls) aged between 4 and 16 years with asthma and allergic rhinitis. Skin prick tests (SPT) were performed with 4 mould allergens: Alternaria alternata, Cladosporium mix, Aspergillus mix, and Penicillium mix. Also, all patients were investigated by SPT to other 17 aeroallergens: pollens, mites, and allergens with animal origin. Results: The study shows that 47 (29.93%) were sensitized to at least one mould allergen. Sensitization rates were as follow: to Alternaria alternata in 36 children (17.56%), to Aspergillus mix in 13 (6.34%), to Cladosporium mix in 12 (5.85%), and to Penicillium mix in 8 (3.9%). Often (n=33, 70.21%) sensitization to moulds were combined with sensitization to aeroallergens from the other investigated groups. Conclusion: This study found a high tendency of sensitization to moulds in children population with asthma and allergic rhinitis. Alternaria alternata was the most common established allergen from this group. In more than two thirds of cases sensitization to moulds was combined with sensitization to other common aeroallergens.