Abstract Based on existing classifications of caves that often involve descriptive terms, a classification is presented that is based purely on genetic processes. An attribute key is developed that allows the classification of caves by means of cave maps, photographs and reports. This method is applied to a dataset of 6007 caves in a study area in eastern Austria. The area comprises diverse geological units of the Eastern Alps and the southern Bohemian Massif. A total of 94% of the caves could be classified with the surprising result that mechanical weathering and erosion caves are almost as common as solution caves even though the vast majority of caves are developed in carbonate rocks. Field checks confirmed the result and showed that the error is acceptable. The classified caves can also be used as indicator of natural phenomena like gravitational mass movements or vulnerable karst areas by decision-makers non-specialized in cave genesis.