INTRODUCTION: Advances in flowable composites including self-adhesive and bulk fill flowable composite resin have been introduced for time saving and better adaptation. OBJECTIVES: was to compare the microleakage and shear bond strength of Self-adhesive& Bulk fill flowable composite resins. MATERIAL AND METHODS: A total of forty non carious extracted human molars were selected for this study. For microleakage test, twenty Class V cavities were prepared on labial surface. Teeth were divided into 2 groups (n=10), Group I: was treated with self-adhesive flowable composite, Group II: was treated with one step self-etch adhesive system with bulk fill flowable composite. Microleakage scores were evaluated on the occlusal and cervical walls and data was analyzed statistically. For Shear bond strength test, twenty molars were embedded in acrylic resin inside plastic molds; the occlusal portion of each tooth was removed. To standardize the bonding area, cylindrical shaped plastic matrices with 4mm internal diameter and 3mm height were used. Specimens were divided into 2 groups (n=10), Group I: was treated with selfadhesive flowable composite, Group II: was treated with one step self-etch adhesive system with bulk fill flowable composite. Shear bond strength was measured using universal testing machine. RESULTS:The cervical margins showed a non-significant higher mean of microleakage scores than the occlusal margins in the two studied restorative materials. Filtek flowable bulk fill composite showed significantly higher mean of microleakage scores than Vertise flow at both the cervical and occlusal margins. Filtek flowable bulk fill composite showed a significantly higher mean of shear bond strength than Vertise flow. CONCLUSIONS: All of the restorative materials used were unable to prevent microleakage. Filtek flowable bulk fill composite showed more microleakage but higher shear bond strength than Vertise flow