The wood preservatives tested on <i>Pinus sylvestris</i> in Bois-le-Roi, France, were:Boliden K 33, Celcure, Wolmanit UAR, Wolmanit UR, Wolmanit CB, KP cuprinol, creosote, and pentachlorophenol. An index of decay is presented for different concentrations of each preservative after 5, 8, 11, 17 and 20 years. Boliden and Celcure are both giving excellent protection; Wolmanit CB is also very effective but at a much higher concentration. Creosote and pentachlorophenol are both very poor. Results of similar tests in this collaborative project in Germany and Sweden are compared with the French results. -- AATA