Measurements of formaldehyde emission from wooden boards, insulation and pains were performed as a part of a project aiming to identify major sources of formaldehyde among construction and finishing products in Danish residential buildings. The methodology of measurements followed standard DS/EN 717-1:2004. The concentrations differed widely between tested materials. The initial concentration ranged from below 0.01 mg/m³ to 0.115 mg/m³ and it dropped below 0.01 mg/m³ for 7 out of 12 investigated materials at the end of measuring period, while for reminding 5 materials it did not changed noticeably. All measured concentrations were below Danish requirements, however performed calculations of formaldehyde concentration in a room finished with investigated materials suggest that indoor concentrations above 0.1 mg/m³ recommended by WHO are well-founded, and concentrations as high as 0.5 mg/m³ can be expected.