This study evaluated and compared microleakage of Repaired amalgam restorations by self–adhering flowable composite and packable composite. Materials and Methods: Thirty extracted human mandibular molars were Collected and class I Coventional cavity prepared followed by amalgam restortation. A simulated defect ( 2–3mm wide, 2mm deep, 3–4mm long) was prepared on restorations, and the molars were assigned to two treatment groups (n=15), Group I: Molars were repaired by Flowable composite (kerr dyad flow), Group II: Molars were repaired by Packable composite (3M Adper easy Bond+3M Filtek Z250). The thermocycled teeth were immersed in 50% silver nitrate dye solution for 24 hours and next they are immersed into the developing solution (Pyrax, India) for six hours. Sectioned mesio–distal direction and then observed under stereomicroscope. Microleakage was evaluated using a 0–4 scale for dye penetration, and data analyzed using Mann Whitney U test. Result: At repair/restoration interface there was a statistically significant difference in mean microleakage scores between two groups that is P= 0.002. Kerr Dyad flow group showed less microleakage than filtek Z–250. Conclusion : None of the restorative techniques evaluated were able to completely eliminate marginal microleakage. Within the limitation of the present study, it can be concluded that there is definite benefit of kerr– Dyad flow a self–Adhering flowable composite resin for repair of amalgam restoration when compared to Filtek Z–250 packable composite.