We spend most of our time indoor and mainly at home. Thermal insulation has greatly improved in the last decades, thus leading to deficiency in ventilation and poor indoor air quality. Many studies suggest that there is a link between respiratory diseases and various indoor air pollutants such as moulds, allergens, volatile organic compounds, combustible smoke, house dust mite, radon or asbestos. This article reviews the most common pathogenic pollutants at home as well as their sources and related respiratory diseases. Preventive measures are further presented for every category of contaminant.