Employing DEA productivity analysis and the Malmquist index, this article investigates the productivity differences and its sources across a set of banks during the last years of the liberal era of the Spanish banking system (1900–1914), which was characterised by major qualitative and quantitative changes in the banking industry. We find evidence of an overall increase in efficiency consequence of increasing competition across banks. Also, our estimates suggest that differences in productivity could serve to explain, at least in part, the subsequent evolution of the different regional banking groups.