Wood being an organic material can be degraded and destroyed by wood-destroying organisms. For this purpose, many wood preservatives have been developed from the past to the present, and are still being developed. In this study, scots pine samples were impregnated with zinc chloride (ZnCl2), nano cerium oxide (CeO2), nano zinc oxide (ZnO) and copper II sulphate (CuSO4) at a concentration level of 0.25%, 0.5, 1, 1.5 and 2.5. Decay resistance against brown (Coniophora puteana) and white (Trametes versicolor) rot fungi attacks has been determined. The antifungal effectiveness of the preservatives was determined for both leached and unleached samples. Furthermore, toxicity in leachate was determined by measuring the mycelium growth of the same fungi species in the petri dishes. Decay test results showed that ZnCl2 was effective in inhibiting both fungi growth on wood samples. In addition, ZnCl2 was found to be the most leach resistant and effective chemical in preventing both decay fungi among the other chemicals. A minimum concentration level of 1.5% was needed for efficient decay resistance for both CeO2 and CuSO4. 1% concentration of ZnO was found to be effective in suppressing the tested fungi attacks in unleached samples, while, all concentration levels in leached samples were not found to be effective to prevent T. versicolor attack. Mycelium growth of the both fungi on leachates was similar to the growth level on references after 2 weeks.