"Sick building syndrome" (SBS) is a group of symptoms experienced by people working in various buildings. This term or another one "building-related illness" (BRI) is used to define illnesses related to non-industrial and non-residential buildings, mainly modern offices, in which people spend many working hours. Specific BRI applies to a group of illnesses with a fairy homogeneous clinical picture and known etiology (infectious, immunological or allergic). Non-specific BRI applies to a group of heterogeneous and non-specific, work-related symptoms, including irritation of skin and mucous membranes of the eyes, nose and throat, headache, fatigue and concentration difficulties. BRI seems to be related to inadequate ventilation, humidity and temperature changes, chemical and biological contaminants from indoor and outdoor sources. Sick building syndrome is considered as an important problem of occupational medicine, bearing in mind that 50% of the entire workforce in industrialized countries work in this type of buildings, and nearly 20-30% of this group of workers report symptoms suggesting the prevalence of sick building syndrome.