Scots pine tar has been used for wood protection in the Nordic countries for over a millennium. Pine tar is in particular used on old traditional wooden buildings and structures and it is important for protection of cultural heritage in the Nordic countries. In the EU review program under the Biocidal Products Directive 98/8/EC (BPD) pine tar was considered as a biocidal active substance (wood preservative) to be evaluated in the review program. However, it was unclear if pine tar had a sufficient biocidal efficacy to fall under the Biocidal Products Directive. In order to clarify that question the Nordic Biocides Group under the Nordic Chemicals Group decided to initiate this study on the fungicidal efficacy of pine tar. This joint Nordic project was carried out by SP Swedish National Testing and Research Institute and supervised by the Nordic Biocides Group under the Nordic Chemicals Group. The project was financed by the Nordic Council of Ministers through the Nordic Chemicals Group, Danish Environmental Protection Agency and the Directorate for Cultural Heritage of Norway.