INTRODUCTION: Dental hard tissue loss is one of the most challenging problems in dentistry. It is caused mainly by two factors, dental caries and erosion. OBJECTIVES: Evaluating and comparing in vitro the effect of two carbonated beverages on bonding of resin-composite material to human permanent enamel surface. MATERIALS AND METHODS: Twenty-four sound human permanent teeth were prepared and divided randomly according to exposure media into two equal groups (I and II). Each group was divided into two subgroups. Subgroups Ia and IIa served as experimental subgroups. Subgroups Ib and IIb were protected from the challenge and served as control. Group I: specimens were exposed to Coca-Cola Regular, group II: specimens were exposed to Fanta Orange; 3x/ 1 minute. Between the challenges, they were stored in artificial saliva for a total of 24 hours. They were then, restored with Adper Single Bond 2/ Filtek Z350 XT nanofilled composite. All specimens were subjected to shear bond strength test. RESULTS: Mann-Whitney U test and Kruskal-Wallis were used to evaluate the difference between the tested groups. Composite material in eroded specimens showed lower bond strength than that in uneroded specimens with no significant difference between the two-erosive media (P>0.05). CONCLUSIONS: Retention of composite resin to enamel surface was affected by acidic soft drinks as evidenced by lower shear bond strength.