Neutron filters/attenuators have been designed and constructed as an upgrade of the JET Gamma- Ray Cameras (GRC's). This diagnostics upgrade should reduce the neutron flux at the gammaray detectors in a way that it would make possible gamma-ray imaging measurements in high power deuterium JET pulses, and eventually in deuterium-tritium discharges. The attenuators will be placed within the GRC diagnostics system between the vacuum vessel port and the camera collimator radiation shields in the case of both the horizontal camera and the vertical one. When the neutron/gamma camera diagnostics is used for neutron measurements, the neutron attenuators have to be moved out of the detector line-of-sight. The operation of the neutron attenuators is controlled by means of an electro-pneumatic system. The radiation performance of the GRC neutron attenuators as well as the response of the gamma-ray detectors have been addressed by means of neutron and gamma-ray transport calculations. The GRC neutron attenuators assembly was installed on a test stand, tested over a period of five months and subsequently delivered to JET.