BACKGROUND AND OBJECTIVE Indoor air quality has become an important factor for sensitization and development of allergic diseases because of increased time spent in homes. We aimed to analyze the possible home-condition risk factors for allergic rhinoconjunctivitis, atopic eczema, and severe disease in schoolchildren aged 5 through 8 years. MATERIAL AND METHODS The parents of 3360 school children in Pamplona, Spain in the 5-8-year-old age bracket answered questions about rhinitis and eczema symptoms from the protocol of the International Study of Asthma and Allergies in Childhood (ISAAC). The instrument contained additional questions about current home conditions related to mold and dust exposure and about conditions in the first year of life. Associations between the allergic diseases and early and current exposure were studied with chi(2) tests and bivariate and multivariate logistic regression. RESULTS Exposure to certain home conditions related to molds and dust in the first year of life increased the risk of allergic disease, but having good isolating windows in the first year of life protected against allergic rhinoconjunctivitis and severe atopic eczema. Some current home conditions were also related to an increased risk of current allergic disease; severe atopic eczema was more common among children with single glazing over the bedroom window. CONCLUSION Current and first-year-of-life home conditions related to dust and mold exposure should be controlled because they influence the prevalence of allergic rhinoconjunctivitis and atopic eczema diseases. Moreover, having a double-glazed window currently and in the first year of life seems to protect against these diseases.