A procedure for assessing the properties of a milling machine based on machining tests was presented, with particular emphasis on shape errors and properties of the workpiece surface layer. The selection of an appropriate test-piece and cutting parameters for such a test was discussed. A mathematical formula was also presented, which allows to associate the accuracy of the test-piece with that of the milling machine. The proposed test procedure was verified by evaluating the DMC 1035V Ecoline vertical machining centre.