This　study　explores　the　dislocation　density　and　configuration　in　fully　pearlitic　steel　wires　during　the　cold　wire　drawing　process　by　X-ray　diffraction　(XRD)　and　transmission　electron　microscopy　(TEM).　The　XRD　results　show　that　the　dislocation　density　increases　from　1.1　x　10(14)　m(-2)　to　1.4　x　10(15)　m(-2),　with　the　drawing　strain　increasing　from　0　to　1.65.　Measurement　methods　by　XRD　and　TEM　for　the　dislocation　density　are　compared.　Dislocation　cells,　walls　and　tangled　dislocations　are　observed　as　the　main　dislocation　substructures　in　ferrite　lamellae.　The　dislocation　cell　size　is　related　to　the　width　of　the　ferrite　lamellae,　which　is　gradually　reduced　with　increasing　drawing　strain.