Abstract: The invention relates to the use of gelatin and a cross-linking agent to provide a medical glue which forms a cross-linked gelatin gel in an area of application of the human or animal body. According to the invention, (i) the gelatin and the cross-linking agent are mixed with each other to form the cross-linking medical glue which is then administered to the area of application; or (ii) the gelatin and the cross-linking agent are made available in separate form and are administered, simultaneously or one after the other, to the area of application while forming the cross-linking medical glue.