The invention provides a grease composition capable of smoothly operating the lubricated parts even under wide-ranging temperature conditions, and at the same time, exhibiting excellent noise reducing effect on the lubricated parts. The grease composition containing a base oil and a thickener is provided, wherein the base oil includes at least one first base oil selected from the group consisting of poly-α-olefins and ethylene-α-olefin oligomers and at least one second base oil selected from the group consisting of polybutene, polyisobutylene, polymethacrylate, and styrene based copolymers, with the first base oil being contained in an amount of 65 mass % or more and the second base oil being contained in an amount of 1 mass % or more and less than 35 mass % based on the total mass of the base oil, the base oil having a kinematic viscosity of 350 to 1400 mm2/s at 40° C., the first base oil having a kinematic viscosity of 300 to 1200 mm2/s at 40° C., and the second base oil having a kinematic viscosity of 1500 to 200,000 mm2/s at 40° C.