A method is disclosed for the automatic contrast medium phase classification of at least one image data record, of the interior of an examination object, generated by way of an imaging system. In at least one embodiment of the method, firstly at least one image data record of the examination object is acquired and metadata associated with the image data record are determined, the metadata including at least one of body region data containing information about a body region of the examination object that is covered by the image data record, and/or measurement time data containing information about a measurement time of the image data record and/or high contrast data containing information about highly contrasty image areas in the image data record. The assignment of the image data record to a contrast medium phase is effected, in at least one embodiment, in a manner dependent on the metadata. Furthermore, a description is given of a corresponding image data record classification device and an imaging system including such an image data record classification device.