A method of automatic washing of vehicles, wherein recirculation and reuse of a substantial proportion of the washing liquid takes place during the washing procedure proper and wherein a principle of counter-flow is used, whereby the vehicle will be washed in a dirtier washing liquid during early treatment states than in later ones. The vehicle is positioned in at least one treatment station, where a plurality of the treatment steps are then carried out, and in the first treatment step treatment liquid is supplied from a first treatment tank and is sprayed onto the vehicle together with additives, if any, and together with impurities originating from the vehicle the liquid thus supplied flows through openings in the floor and is returned to the first treatment tank. In this manner a substantial proportion of the treatment liquid is reused and in the following treatment step treatment liquid is supplied from a second treatment tank to be sprayed onto the vehicle together with additives, if any, and is then, after drainage, returned to the second treatment tank, and so on, to be used in the subsequent treatment step, so that in each treatment step a treatment tank specific for that particular treatment step is used and reuse of a substantial proportion of the treatment liquid takes place. Each treatment tank is also replenished with a supplementary amount of liquid.