The aim of the present study is to highlight the kind of indoor aeroallergens and assess their role in asthma severity in children from Annaba city (Algeria). Our study concerned 68 asthmatic children and 50 healthy children. All children's blood samples were obtained to determine biological parameters, followed by home visit to these children to assess meteorological parameters and fungal exposure. It was found that the asthma severity was associated with eosinophilia (χ2, p = 0.01), rate of total IgE (χ2, p < 0.001) and sensitization to indoor aeroallergens. This association between the severity of the disease and sensitization was strengthened with the presence of mites (χ2, p < 0.01) and pets, namely cats (p < 0.001). Moreover, all houses of asthmatic children contain fungal spores, which were also associated with the sensitization to fungi (χ2, p < 0.001). The average indoor temperature and humidity in the houses of asthmatic children represent favorable conditions for the growth of mold and development of mites, whose presence, especially Cladosporium and Alternaria, was associated with sensitization to fungi and severity of asthma. The strongest sensitization was found with dust mites (Dermatophagoides pteronyssinus, Der p1 (d1) and Dermatophagoides farinae, Der f2 (d2)) which is closely associated with asthma severity.