Internal corrosion of natural gas pipelines is a major cause of many related accidents. In addition to the metal loss due to corrosion, hydrogen ions produced during corrosion can lead to the degradation of ductility of metals used in these pipelines. The effect of hydrogen generated through internal corrosion on current pipeline steels was studied. Three grades of API 5L steels commonly used in natural gas infrastructure were investigated: X56, X65, and X100. The rates of hydrogen diffusion were determined electrolytically via a Devanathan-Stachurski cell. The steels were subjected to hydrogen embrittlement tests using electrolytic hydrogen charging and constant strain rate tensile tests. The microstructure analysis of the investigated materials and the fracture surfaces was performed via scanning electron microscopy (SEM). This presentation reports on work to extend the life of the natural gas pipeline network via understanding the mechanisms of hydrogen ingress and subsequent embrittlement induced by corrosion processes.