Purpose: Cavity disinfection is an essential procedure for success of Atraumatic restorative treatment. This study was designed to test the efficacy of diode laser and grape seeds extract as primary teeth cavity disinfectants.Methods: A total of 96 sound primary molars were divided into two groups according to the test performed (n=48); antimicrobial effect/ shear bond strength. Each group was subdivided into four subgroups according to cavity disinfectants: (n=12); group1: Control (no treatment), group 2: 2% chlorhexidine gluconates (CHX), group 3: diode laser, group 4: 5%w/v grape seed extract (GSE). Occlusal cavities were inoculated with the Streptococcus mutans (S.mutans) suspension and incubated under aerobic conditions. Dentine chips were collected and S.mutans colony forming units were counted. For shear bond strength, cylindrical glass ionomer specimens were bonded to dentine surface then loaded at tooth-restoration interface till debonding.Results: Diode laser exhibited the highest antibacterial effect. No difference was detected in mean values of shear bond strength in diode laser (5.88±1.28) and GSE (3.47±1.55) groups when compared to the negative control group (4.97±1.80). Conclusion:Diode laser system is preferred over GSE and CHX as a potent cavity disinfectant for primary teeth. GSE can be used as a natural alternative for CHX