A method of processing oily sludge to remove a substantial proportion of the water and hydrocarbon content therefrom to form a solid cake of waste material that is suitable for disposal in land fill sites. The method involving, firstly promoting flocculation in a batch of waste material by mixing in a flocculating agent. The flocculated waste material is then pressing at a first pressure to extract substantially all the free water within the mixture. After the first pressing the waste material is subjected to a second pressing at a second pressure to extract a substantial proportion of hydrocarbon material and further water from the mixture, thus leaving a solid cake of waste material. The invention also considers additional processing steps to maximize the level of hydrocarbon material reclaimed from the waste material.