Hydrogen permeation experiments were carried out to investigate the effect of thallium on hydrogen entry into HY-130 steel. These experiments show that the presence of thallium ions in an electrolyte drastically increase the hydrogen entry rate. The hydrogen entry efficiency and hydrogen surface coverage were increased by a factor of 10 and 6, respectively. In order to fit the permeation experimental data, the Iyer-Pickering-Zamanzadeh (I-P-Z) hydrogen permeation model was modified by including a mass-transfer term in the discharging equation. The relationship between hydrogen permeation and the hydrogen evolution reaction were investigated and new relationships were obtained.