The ESA cornerstone mission GAIA will perform astrometric, photometric and spectroscopic measurements and is due for launch in 2010 into L2 orbit. The astrometric telescope system will catalogue the position of over 109 objects down to 20th magnitude and perform broadband photometry. The spectroscopic telescope will provide narrow-band photometry and feed a Radial Velocity Spectrometer which will accurately determine the radial velocities of objects down to 17-18 magnitude. This paper discusses the characteristics of the detectors envisaged for the focal plane of the RVS instrument.