Statement of the problem: Delamination of veneering porcelain from underlying ceramic substrate has been reported to zirconia based restorations. The bond strength of zirconia veneer has been considered a weak link in the layered all-ceramic restorations.Purpose: The aim of this investigation was to evaluate the shear bond strength of CAD\CAM zirconia restorations veneered with different techniques: CAD veneering technique with glass joining, CAD veneering technique with adhesive resin bonding and conventional layering technique.Materials and Methods: Fifteen zirconia based discs constructed with CAD\CAM system veneered with different techniques and with standardized dimensions (zirconia discs with 6 mm diameter and 2 mm thickness, veneering ceramic discs with 4mm diameter and 2 mm thickness) were tested in this study. The fifteen zirconia discs were divided into three groups according to the method of veneering: Group 1: zirconia core bonded by fusion glass ceramic to lithium disilicate veneering material constructed by CAD/CAM technique (n=5), Group 2: zirconia core bonded by adhesive resin to lithium disilicate veneering material constructed by CAD/CAM technique (n=5) and Group 3: zirconia core veneered with nano-fluorapatite veneering material using conventional veneering technique (n=5).Results: It was found that Group 3 (Conventional layering) recorded the highest Statistically significant (P<.0.5) shear bond strength mean value (74053 ± 2052MPa) followed by Group 1 (CAD on) (24022 67056 MPa) while Group 2 (Rapid layer) showed the lowest statistically significant shear bond strength mean value(23027 ± 2022 MPa) as indicated by ANOVA test followed by pair-wise Newman keuls post-hoc tests.Conclusions: Conventional layering of zirconia still represents reliable method for zirconia veneering.