To obtain a flexible epoxy putty composition suitable for forming a smooth surface by ironing by using a spatula into surfaces of various substrates such as bumper, wood, metal, lightweight concrete and the like which need flexibility.

This flexible epoxy putty composition is obtained by blending organic microballoons having ≤100 μm particle size in an epoxy resin composition comprising an epoxy resin, a curing agent and an extender pigment. Preferably, 5-50 pts.wt. of organic hollow microspheres having 0.1-0.3 g/cm3 density or 0.5-5 pts.wt. of organic fine foamed powder having 0.01-0.05 g/cm3 density is blended with 100 pts.wt. of the sum total of the epoxy resin and the curing agent.