Good quality ADP-KDP mixed crystal (90:10) is grown by slow cooling method. The size of the grown crystal is 80 x 10 x 10 mm(3). The mounted seed size was 5 x 10 x 10 mm(3) and the crystal was grown along the 'c' axis. HRXRD studies have been done in the near and far regions of the seed crystal. The FWHM of these diffraction curves are 28 and 29 arcsec, which are almost the same. The close values of FVVHM of both the specimens indicate that the quality of the crystal remains nearly the same throughout the crystal. 80% of transparency is observed from the UV-vis studies in the entire visible region. Vickers hardness studies indicate that the mixed crystal is mechanically more stable compared to the ADP. Higher piezoelectric coefficient is observed in mixed crystals. Dielectric measurements are carried out. From the laser damage threshold studies, it is observed that higher energy is required to damage the mixed crystal and it indicates that the laser stability of the mixed crystal is high. (C) 2011 Elsevier B.V. All rights reserved.