The invention relates to a method for producing a hollow structure and particularly a method for producing a closed and filled hollow structure. Furthermore, the present invention relates to a hollow structure and preferably a closed and filled hollow structure obtainable by a method according to the present invention as well as to a tool for producing such hollow structure and/or for performing a respective method. More particularly, the hollow structure according to the present invention as well as the filling is at least partially flexible and/or can be brought into a flexible condition. The method for producing a filled hollow structure comprises the steps: producing an open hollow structure of a first material positioning the open hollow structure on a tool for holding the open hollow structure filling the open hollow structure with a filler medium closing the filled open hollow structure by means of clamping jaws providing a cavity and filling the cavity with a second material for closing the open hollow structure.
