Objective: The aim of this study was to compare the microleakage of new all-in-one adhesive systems on enamel and dentin margins with that of a conventional total-etch system. Method and materials: Thirty buccal Class V cavities were prepared with enamel and dentin margins in 30 bovine teeth and randomly divided into three groups of 10 specimens each. Group 1 was bonded with Etch & Prime, group 2 with Prompt L-Pop, and group 3 with 35% phosphoric acid plus Prime & Bond 2.1. After being stored in an environment of 100% humidity for 24 hours, the teeth were immersed in a 50% silver nitrate solution for 24 hours and then put in a developing solution for 15 minutes. The specimens were sectioned vertically and buccolingually, and microleakage was evaluated on a scale of 0 to 3. Results: For the enamel margin, statistical analysis revealed that there was no significant difference between groups 1 and 2 or groups 1 and 3 but that there was a statistically significant difference between groups 2 and 3. Statistical analysis revealed no significant difference among the groups in dentinal microleakage. Conclusion: Among the three adhesive systems used in this study, Prompt L-Pop provided the least microleakage in enamel; however, there was no statistically significant difference among the groups on dentin margins.