In the last years, Economic History literature has paid close attention to the long-term changes undertaken by regional income inequality in diferent countries after the integration of their domestic markets. Nevertheless, this literature has mainly focused on developed economies (US and Europe). New evidence is required from peripheral economies, where economic growth has had different features, and income inequality may have been dominated by other forces and followed different trends. The aim of this paper is to analyse several dimensions of the long-term evolution of Mexican regional income inequality, from the early stages of domestic markets integration to the present (1895–2010). This analysis may be taken as basis for further explanatory analysis and may contribute to the emergence of new hypothesis to explain the long-term changes in regional inequality in peripheral economies.