Aim of the study: The aim of the study is to evaluate the effect of chlorhexidine and/or ethanol pre-bonding treatment on the shear bond strength of resin composite to dentin using etch and rinse adhesive system after 24 hours, 3 months and 6 months of aging. Materials and methods: Dentin surface of premolars were etched and randomly assigned into 4 groups (n=24). In Group A, dentin surfaces were bonded according to the manufacturer’s instruction. In Group B and C, dentin surfaces were treated with 2% CHX or 100% ethanol for 60 sec respectively. In Group D, dentin surfaces were treated with 2% CHX for 60 sec followed by 100% ethanol for another 60 sec. The adhesive resin was then applied and light cured according to the manufacturer’s instruction. Resin composite build ups were made above the dentin surface for shear bond strength test after 24 hours, 3 months and 6 months’ storage period in normal saline. Bond strength data were analyzed using one-way ANOVA and Tukey’s test. Mode of failure was also analyzed whether adhesive, cohesive or mixed between composite and dentin. Results: Significant differences were found for the 2 factors: ‘storage period’ (p<0.05) and ‘adhesive protocol’ (p<0.05) on bond strength. Numbers of mixed failure were higher when dentin surfaces were treated with 2% CHX and/or 100% ethanol. Conclusion: Dentin surface treatment with 2% CHX and/or 100% ethanol was effective in reducing the deterioration in shear bond strength of composite to dentin up to 6 months of storage.