Inequalities in remuneration — not only between men and women, but also between nationals and non-nationals — is a worldwide phenomenon. Depending on the countries, over the past decades, the wage gap has diminished, stagnated or reverted. The phenomenon has been made more complex with the extension of part-time work, particularly in industrialized countries. A careful analysis of wage discrimination at each national level is necessary, as it could be linked to a series of factors including women's employment structure and wage-fixing mechanisms.

The relevant ILO instruments concerning wage discrimination are Convention No. 100 and Recommendation No. 90 on equal remunneration for men and women for work of equal value.