The present invention provides wood preservative compositions comprising micronized particles. In one embodiment, the composition comprises dispersions of micronized metal or metal compounds. In another embodiment, the wood preservative composition comprises an inorganic component comprising a metal or metal compound and organic biocide. When the composition comprises an inorganic component and an organic biocide, the inorganic component or the organic biocide or both are present as micronized particles. When compositions of the present invention are used for preservation of wood, the micronized particles can be observed as uniformly distributed within the wood and there is minimal leaching of the metal and biocide from the wood.