Introduction: Composite is one of the widely used aesthetic restorative material since 1960’s. For decades, conventional composites were placed in maximum increments of 2 millimetres, because of the limited depth of cure. Bulk–fill composites are introduced as an alternative to the incremental layering technique which claims to enable restoration in thick layers up to 4 – 6 mm .So the aim of the study is to evaluate and compare the depth of cure of three bulk–fill composite restorative materials. Material and methodology:Nanofilled bulk–fill material (Filtek Bulk Fill Posterior Restorative), nanohybrid bulk–fill material (Tetric N–Ceram Bulk Fill) and posterior bulk–fill flowable resin material (SureFil SDR flow).The depth of cure was assessed according to International Organization of Standard ISO 4049: 2009 and the data collected was statistically analyzed Results : The mean depth of cure values for SureFil SDR flow were 4.37±0.16 mm, followed by Filtek Bulk fill Posterior 3.84±0.15 mm and Tetric N Ceram Bulk Fill 3.64±0.22 mm. Conclusion: Within the limitation of the study posterior bulk–fill flowable resin material (SureFil SDR flow) showed the highest depth of cure than nanohybrid bulk fill composite (Filtek Bulk Fill Posterior Restorative and Tetric N Ceram Bulk Fill).