A grease composition comprising a thickener and a lubricating base oil, wherein the lubricating base oil has a viscosity in the range of from 5-1000 cSt (at 40° C.). The thickener is present in an amount of 5-40 wt. %, based on total weight of the grease composition. The thickener comprises an ester terminated oligomer which has the general formula: “R1—O—[CO—R2—CO—NH—R3—NH—CO—R2—CO]n-O—R1”. “R1” represents a hydrocarbon group containing 4-22 carbon atoms. “R2” represents a hydrocarbon group containing 4-42 carbon atoms. “R3” represents a hydrocarbon group containing 2-9 carbon atoms. “n” represents an integer in the range of 1-20. The weight ratio between the lubricating base oil and the ester terminated oligomer (oil/oligomer) is larger than 1. The grease composition can be used for lubricating a mechanical component having a metal surface and/or for protecting a mechanical component having a metal surface against corrosion, wear and/or fretting.