A corrosion resistant steel cord for reinforcing rubber articles, particularly a belt and/or carcass of a pneumatic tire, has a residual compressive stress inside the twisting helix of each steel filament such that a ratio R.sub.1 /R.sub.0 is less than one, where R.sub.0 is the radius of curvature of a helix in each helically formed steel filament obtained by untwisting of the cord and R.sub.1 is the radius of curvature of the helix after removal of a surface layer from the inside of the helix in the steel filament. The steel filaments have a tensile strength of 4,000-4,800 N/mm.sup.2. The cord does not have a wrapping wire around its outer peripheral surface and has either a single twisted construction obtained by twisting 3 to 6 steel filaments in an open structure having a space between adjacent filaments or a two-layer twisted construction obtained by surrounding a core of n=1-4 steel filaments with a sheath of n+(2-6) steel filaments in a rubber penetration structure having a space between adjacent filaments of the sheath or a three-layer twisted construction obtained by surrounding a core of a single steel filament with a first sheath of m=3-6 steel filaments and a second sheath of m+(2-6) steel filaments in a rubber penetration structure having a space between adjacent filaments of each sheath.