Abstract: After selective caries excavation, silver diamine fluoride (SDF) can be used to stop the caries from progressing further. Aim: This in vitro study was directed to evaluate the effect of silver diamine fluoride on micro-shear bond strength of carious primary molars. Material and method: Experimental in vitro controlled study, carried out in Pedodontics and Oral Health Department, Faculty of Dentistry (Boys, Cairo), Al-Azhar University. A total of 36 teeth were used in this study for shear bond strength test were divided into four equal groups (n= 9). The collected data during the study were tabulated and statistically analyzed. Results: application of SDF resulted in insignificant increase in the micro-shear bond strength of RMGIC and GIC to the carious dentine. The cohesive failure of GIC and RMGIC alone or with SDF was the lower when compared to the adhesive and mixed types of bond failure. While, the adhesive bond failure mode was the higher among the investigated failure modes in the both groups. Conclusion: SDF did not adversely affect the bond strength between the GICs restoration and the carious dentine. SDF insignificantly increase the bond strength between the GICs restoration and the carious dentine. RMGIC has the higher micro-shear bond strength to carious dentine than the conventional GIC.