Abstract: The present invention relates to a process for preserving wood, in particular hardwoods, against attack by living organisms, e.g. fungi and insects, which destroy wood. In particular, the present invention provides a one or two step process for preserving wood against fungal and/or insect attack. The fungicide treatment step comprises introducing a copper solution or a copper solution into wood. The insecticide treatment step comprises introducing a chromium and arsenic solution into wood. If the pH of the wood system is controlled, both steps may be carried out simultaneously so as to preserve the wood against fungal and insect attack. Alternatively, the insecticide treatment step may follow the fungicide treatment. Where only protection against fungus is desired, the process comprises introducing copper and arsenic solution into wood. On the other hand, if only an insecticide treatment is required, the process comprises only the abovementioned insecticide treatment step.