IBIS (Imager on Board INTEGRAL Satellite) is an instrument designed to product images of the gamma-ray sky in the 15 keV to 10 MeV energy range with few arcminute resolution over a wide field of view. This will be obtained by deconvolving the shadowgram projected by a coded mask onto two pixellated detectors layers. One, ISGRI (INTEGRAL Soft Gamma-Ray Imager) is made of 16384 CdTe elements operating in the low energy range (15 to 1000 keV), the other, PICsIT (Pixellated Imaging CsI Telescope) is made with 4096 CsI(TI) scintillating crystals coupled to PIN PhotoDiodes (PD) and it operates in the high energy range (0.1 to 10 MeV). Theoretical performances of the overall instrument have been described in a dedicated session at SPIE in August 1996(1,2). Now, after many tests on the various components available for the construction of the PD-CsI(TI) detectors, the procedure for the industrial manufacturing has been defined and a first lot of detectors has been tested. In this paper, after a short description of the detector assembly and test procedures, the performances of a significant number of the PICsIT detector units are reported.