The petroleum based diglycidyl ether of bisphenol A (DGEBA) epoxy resin is one of the most extensively used epoxy resins for various industrial applications such as paints, coatings, adhesives, and structural applications, owing to its excellent mechanical and thermal properties, low curing shrinkage, and good chemical resistance. However, the serious drawbacks in terms of brittleness or poor fracture energy significantly restricted its extensive utilization. Various renewable resources based flexible chains were used to blend with DGEBA for toughening and to significantly improve the fracture properties without sacrificing the mechanical properties. This review mainly focuses on toughening of DGEBA with various renewable polymers and the effect of its concentration on its toughening mechanism.