The use of forced vibration tests for the dynamic acceptance of machine tools enables the chatter performance to be assessed for a wide range of cutting conditions, from a single test set-up, this corresponding to a particular configuration of the machine. However, to cover the expected working range of the machine, other test configurations must be considered, for example relative positions of the table and spindle, etc. The factors to be considered in the selection of these test conditions are discussed in relation to test results for various types of machine tools.