Macroscopic measurements of fracture surfaces were found to be vital for the development of a model of hydrogen stress cracking (HSC). This type of cracking can occur in buried natural gas pipelines exposed to aggressive external environments in which cathodic protection reactions can produce damaging hydrogen. The model, which is based on a 3-stage crack growth mechanism, allows crack initiation conditions and times-to-failure to be predicted. It was developed with results of laboratory tests on X60 steel and 3-stage crack growth data obtained from the examination of resultant fracture surfaces. These examinations involved analysis of scanning electron and optical microscope images which enabled the maximum stress intensity factors to be calculated for each stage of crack growth. This paper describes the fractography methods and possible applications for a HSC model.