User acceptance testing of newly installed gamma cameras is mandatory in order to verify manufacturers' specifications and to ensure optimal image quality. Acceptance test procedures are widely standardized today and are carried out following commonly accepted test protocols. Two new triple head gamma cameras have been installed during the last year at the Department of Nuclear Medicine of the Vienna University Hospital. For acceptance testing of these cameras a modified and expanded version of the commonly used test protocol for single head SPECT systems has been employed. Details of the tests that have been carried out and a comparison of the results obtained for both cameras are presented. Furthermore, some specific problems that are encountered during acceptance testing of multiple head systems are discussed. In particular it has been noted that some important tests of intrinsic camera parameters cannot be carried out, which makes a complete verification of vendors' specifications impossible. In spite of these problems the acceptance test system for multiple head cameras presented in this work was sufficient for establishing proper working conditions for clinical use.