A method and an associated apparatus for washing rock samples, which is particularly suited to the washing and preparation of rock samples obtained from oil and gas wells. In one embodiment there is provided a method of washing rock samples involving a plurality of discrete rock samples; providing a plurality of sequentially arranged discrete washers each of which is spaced from a respective washing position and configured to direct a washing flow of water towards said washing position; and automatically conveying said samples relative to said washers so that each sample moves in succession through said washing positions for sequential washing by each said washer.