Objective: The main cause of failure of composite resin restorations is volumetric shrinkage. The aim of this study was to analyze and compare volumetric shrinkage in nanohybrid and nanoceramic composite resins. Methods: A total of 32 (3 cm×3 cm× 2 mm) cavities were analyzed for volume using micro-CT. The samples were divided randomly into two groups: 16 cavities that were restored using nanohybrid composite resin and 16 cavities that were restored using nanoceramic composite resin. The composite resin volume was analyzed using micro-CT. Results: The difference in volumetric shrinkage between nanohybrid composite resin 245,866.5 mm3 (3%) and nanoceramic composite resin 3,470,175.13 mm3 (5%) was not significant (p=0.585). Conclusion: Nanohybrid and nanoceramic composite resins have the same volumetric shrinkage rate. © 2020 The Authors.