A technique has been developed to create diamond-like carbon (DLC) coatings on the interior of steel pipe. The coating exhibits high hardness high adhesion low coefficients of friction and good wear resistance in dry and wet sand slurry environments. A testing program was undertaken to test the resistance of this DLC coating to attack by high pressure and temperature CO2/H2S in laboratory autoclaves. Results indicate that newer formulations of DLC coating are highly resistant to simulated hot sour environments even when the coatings have been deliberately mechanically damaged prior to testing indicating that DLC coatings may significantly extend component life in abrasive hot sour applications in the oil and gas industry.