Abstract: The cavitation erosion (CE) behaviour of X65 pipeline steel subjected to electrochemical hydrogen-charging was inves-tigated in both deionized water and a 3.5 wt.% NaCl solution. The findings reveal that hydrogen embrittlement signifi-cantly impacts CE behaviour of the steel. While electrochemical hydrogen-charging slightly improves its corrosion resistance, it notably reduces the steel’s resistance to CE. Additionally, the mass loss due to CE shows a positive correlation with hydrogen-charging current density. For pipeline steel under any hydrogen-charging current density, the combined effects of CE and electrochemical corrosion account for nearly half of the total mass loss attributed to CE damage. Additionally, the role of corrosion in exacerbating CE, regardless of hydrogen-charging, is a critical factor that warrants the attention. Electrochemical hydrogen-charging plays a pivotal role in the degradation of CE resistance in pipeline steel.