A lubricating oil composition of the present invention for an internal combustion engine is prepared by blending (A) a perbasic calcium sulfonate and/or a perbasic calcium phenate having a TBN of 200 mgKOH/g or higher, (B) predetermined binuclear and/or trinuclear organic molybdenum compounds, and (C) a polyalkyl (meth)acrylate having an SSI of 30 or lower into a lubricating base oil composed of a mineral oil and/or a synthetic oil, in which the total content of molybdenum derived from the binuclear and trinuclear organic molybdenum compounds is 0.025% by mass or higher based on the total amount of the composition, and in which the lubricating oil composition has a high-temperature high-shear viscosity at 100° C. of 4.0 to 5.0 mPa·s, a high-temperature high-shear viscosity at 150° C. of 2.5 mPa·s or lower and a NOACK value (250° C., 1 hr) of 15% by mass or less.